Dr. Seth M. Holtzman
                                                            ASSISTANT PROFESSOR OF PHILOSOPHY
 
 

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REEXAMINING PRESUPPOSITION¹

With the recent publication of a volume on P. F. Strawson in the Library of Living Philosophers, Strawson's significant influence on the philosophical landscape is now more evident than ever.²  Surprisingly, though, even this most recent critical evaluation of Strawson's work has overlooked one of Strawson's most important achievements: for many philosophers, the dominant model of presupposition still carries Strawson's influence.³  Others have sometimes modified Strawson's model; but it is safe to say that a broadly Strawsonian account prevails, at least among philosophers who still believe that there are presuppositions.
 

Nevertheless, I find serious problems with the Strawsonian account.  In fact, I agree with David Cooper that "no adequate account of presupposition has been given by logicians or philosophers, even for their own purposes."⁴  Yet, presuppositions play an important, if not central, role in philosophical inquiry.  Philosophers need a correct understanding of the nature of presupposition; the discipline is not healthy when we are unclear about presupposition.⁵ This state of affairs leads me to offer a substantially different account of presupposition.  First, we will examine some insights about presupposition drawn from ordinary language.  Then we will locate some of the points where the Strawsonian account fails.  Moving out of the Strawsonian account, we will work toward a more satisfactory account of the nature of presupposition.  Lastly, we will note the explanatory power of this new account.
 
 

Beginning within ordinary language, we find that concepts such as assumption, supposition, and presumption are similar to the concept of presupposition.⁶  Each picks out something taken for granted; each locates an antecedent condition.  For example, when unmarried Cindy is asked if her husband is at home, she could point out that the question falsely presupposes that she has a husband.  Then again, Cindy might have said that the question falsely presumes (or assumes or supposes) that she has a husband.  People tend not to employ the concept of presupposition consistently and carefully, often conflating it with some of its near conceptual relatives.  Even the Oxford English Dictionary reflects this confused usage.⁷  But the concepts of assumption, supposition, and presumption share features decisively different from presupposition.  Let us consider some of those features.
 

We have grammatical ways of introducing assumptions, suppositions and presumptions explicitly; call them "postular" grammatical devices.⁸  For example, we have imperative usages, as in "Assume you are healthy" and "Suppose that she is gone".  We have a performative usage, as in "I (hereby) presume he died".  We have parenthetical usages, such as "Reflective people, he supposed, are wise".  We have adverbial usages, such as "Fred supposedly believes in witches;" in fact, "assumably" is a word, though it is rarer than "supposedly" and "presumably".  And we have other usages, such as prepositional and participial phrases: "On the assumption that you eat, you live"; "She misjudged his underlying physical condition, supposing he was healthy."
 

But no postular devices can introduce presuppositions explicitly, as the following examples make clear: "Presuppose that physical objects are real"; "I (hereby) presuppose that there are sense data"; "Apples, he presupposed, might be within reach"; "She presupposedly decided that she could finish the task"; "On the presupposition that the boat is good, they will take to the sea in it"; and "Presupposing that he knew the city, he set off walking".⁹  Clearly, these locutions make no sense.
 

The verbs "assume", "suppose" and "presume" denote acts.  It makes sense to say, "I assume (suppose/presume) that he left".  One makes an assumption.  One performs these acts of assuming, supposing and presuming.  These verbs locate acts that can be qualified by manner; the verbs may be modified adverbially.  We may say, "I assume q reluctantly", "He is presuming q foolishly" or "She thoughtfully supposed that q".
 

The verb "presuppose", though, does not locate an act.  To the question, "What is he doing?", it is not meaningful to reply, "He is presupposing that q."  Of course, we can say, "He is presupposing that q."¹⁰  But personal and impersonal usages of this sort are shorthand for saying that something about a person, such as her belief, statement, action, experience or knowledge, presupposes q.  Predictably enough, presupposing is not qualified by manner; the verb may not be modified adverbially.  It makes no sense to say, "I presuppose q reluctantly" or "He is presupposing q foolishly" or "She thoughtfully presupposed that q."
 

The terms "assumption", "supposition", and "presumption" can refer either to the acts of assuming, supposing and presuming or to what is assumed, supposed, presumed.  Consider cases in which these terms refer to acts.  These mental acts provide grounds for further acts of reasoning.  One acts by means of assuming or presuming or supposing; then one can reason forward from the assumption, supposition or presumption to a conclusion.  And one can reason "backward" from one's conclusions to locate their assumptions, suppositions and presumptions.¹¹
 

In sharp contrast, we cannot reason forward from presuppositions.  As we have seen, no postular devices exist to introduce them.  Presupposing is not an act, and therefore cannot lead forward to other acts of reasoning.  A presupposition does not function in our reasoning in that manner.  We can, however, reason backward from one of our commitments to an antecedent condition that is its presupposition.  This fact provides one clue to its nature, as we will see later.
 

Given what we have said about assumptions, suppositions, and presumptions, it makes sense to think of them as truth-conditions.  We put them forward as truth-conditions of something else; they are antecedent conditions in this sense.  When a conclusion takes for granted a supposition, it is in the sense that a supposition is a truth-condition of that conclusion.¹²
 

Modern formal logic agrees.  For example, an assumption in deductive logic is a simple truth-condition of a conclusion; the assumption entails its conclusion.  A second assumption might equally well support that same conclusion, so if the first assumption is false, the conclusion need not be false.  Conclusions, on the other hand, are entailments; and entailments are strict truth-conditions.  If the conclusion is false, the assumption leading to that conclusion must be false.  In non-deductive logic, an assumption need not entail the conclusion; the assumption is instead often an evidential basis for a conclusion.  The truth of the assumption makes its conclusion more likely to be true than without it.  Even in non-deductive logic, an assumption is a truth-condition.
 

The question is, what kind of condition is a presupposition?  First, let's start with some apparent examples of presuppositions.  The question "Have you stopped forging checks?" presupposes inter alia that you once forged checks.¹³  No direct "yes" or "no" answer evades the presupposition.  Only sidestepping the question by explicitly denying its presupposition--"I never forged checks"--allows one to assert one's innocence.  The imperative "Row the boat" presupposes the rowing ability of the person commanded to row.  It can neither be obeyed nor disobeyed if the presupposition is false and the person cannot row.  Both the statement "The unicorn ate a rose in the garden" and its negation "The unicorn did not eat a rose in the garden" presuppose that there are unicorns.  The statement cannot succeed at being true or false if the presupposition is false and there are no such things as unicorns.  The concepts "red" and "not-red" presuppose the concept of extension.  If the concept of extension were not meaningful, then neither would the concepts "red" and "not-red".¹⁴
 

Call something a "presupposer" if it carries a presupposition.  A presupposition certainly does not seem to be a truth-condition.  After all, questions and imperatives and concepts can be presupposers.¹⁵  If questions, imperatives and concepts are not the kinds of things that have truth-values, a presupposition is prima facie not a truth-condition.  The way a presupposition governs statements with opposite truth-values also argues against a truth-conditional analysis of presupposition.  If statements S and ~S both presuppose statement S', then S' cannot be a truth-condition of S as well as ~S, on pain of logical inconsistency and absurdity.  Lastly, presupposition failure reveals another reason.  As Strawson points out, a failed presupposition undermines not the truth of its statement-presupposer but its being truth-valued, i.e., its being successful as a statement.¹⁶  These are not marks of a truth-condition.
 

A presupposition appears to be a necessary condition of some sort.  The statement "The unicorn ate a rose in the garden" does not simply happen to presuppose that unicorns exist; it could not fail to have that presupposition.  In general, to be logically committed to the statement-presupposer logically requires commitment to its presupposition(s).  Van Fraassen notes that "What implication and presupposition have in common is that, if A presupposes or implies B, the argument from A to B is valid."¹⁷  He speaks of A necessitating B.  So, yet another point separates presupposition from its conceptual cousins.  Assumptions, suppositions and presumptions need not be necessary conditions.  A presupposition, though, is inherently a necessary condition.
 

We have so far marshaled evidence that a presupposition is a much different sort of beast than an assumption, a supposition, or a presumption.  Yet a surprisingly large number of philosophers continue to conflate presupposition with these (and other) related concepts.  Stalnaker, for example, says, "A person's presuppositions are the propositions whose truth he takes for granted, often unconsciously, in a conversation, an inquiry, or a deliberation.  They are the background assumptions that may be used without being spoken--sometimes without being noticed...."¹⁸  One of the strengths of the Strawsonian account is that it avoids this sort of conflation.
 
 

To understand Strawson's position, we should first recall Bertrand Russell's work briefly.  In developing his logical atomism, Russell proposed a theory of reference that would make sense of problematic non-referring propositions such as "The present king of France is bald."¹⁹  Instead of concluding that the definite description "the present king of France" is a referring (or denoting) expression, as Meinong and others had done in various ways, Russell argued that this definite description is non-denoting.  He proposed that for purposes of philosophical clarification the given proposition should be understood, not as having an atomic subject-predicate form, but as having a complex existential form.  Logical analysis, he contended, reveals the proposition's logical form to be this: There exists an x, such that x is a present king of France and, for all y, y is a present king of France if and only if x=y and x is bald.  Russell's logical analysis, if correct, showed that the proposition in question does not carry a commitment to the existence of a (non-existent) present king of France, because the offending description is not expressed by any element, any logical atom, in the logical form.  Russell was in effect contending that the claim "There is a present king of France" is part of what someone asserts with the proposition.  If no king of France exists, the first conjunct would be false, and so too the entire proposition.
 

The Russellian analysis of definite descriptions was Strawson's point of departure, and Strawson took issue with Russell's assimilation of presupposition to assertion.  Strawson argued that the meaning of a sentence is determined by rules or conventions, such as syntactic ones, and that reference and therefore truth or falsity are determined only by the sentence-in-use, i.e., by the statement made.  He agreed with Russell that assertions with this kind of problematic definite descriptions are meaningful, but he denied that these assertions are false.  Yet, he also denied that these assertions are true, for a truth-condition of such an assertion is the existence of the object apparently referred to by the problematic definite description.  One who utters "The present king of France is bald", Strawson argued, is not asserting even in part that there is a present king of France.  But the utterer, in making this statement, is nonetheless relying on the claim that there is a present king of France.  In the context of uttering this sentence, the utterer is committed to the truth of the claim that there is a present king of France.  The commitment comes not through assertion but through presupposition; the statement presupposes that there is a present king of France.²⁰
 

It was in this philosophical context that Strawson needed an account of presupposition.  In a passage from An Introduction to Logical Theory, he discussed the presupposition relation:

Strawson unpacks the kind of necessitation involved in presupposition in terms of entailment.  That is, he explicates "necessary condition" in terms of entailment: if S' is a necessary condition of S, then S entails S'.  If we assume (with Strawson) a bivalent logic, then on Strawson's view, S presupposes S' iff (S entails S') & (~S entails S').  Here the presupposition relation is explicated in terms of the power of the presupposition to govern the truth-value of both its positive and negative presupposers.  The presupposition relation is defined as a dual entailment; this is why he holds that implication by presupposition is not equivalent to one-way entailment.  A presupposition is not a truth-condition; it is a necessary condition of the presupposer being well-formed and thus successful as a statement at all.  A presupposition is a necessary truth-value-condition of a statement.
 

Russell's work was primarily concerned with statements and parts of statements.  Given that Strawson's account of presuppositions developed in response to Russell's theory of descriptions, it is not surprising that Strawson emphasized the presuppositions of statements and parts of statements.  It is an oft-told tale that ordinary language philosophers were at pains to emphasize that language does more than simply state and that the logical atomists' concern with language was biased toward statements only.  Even though the ordinary language movement influenced Strawson (note his interest in the use of sentences), he worked out his account of the presupposition relation almost entirely in terms of statement-presupposers and statement-presuppositions--and thus in terms of truth-values, truth-valuelessness, entailment, and the implications of presuppositions for formal logic.
 

Any account of presupposition that handles only statements is suspicious on its face.  Unfortunately, although Strawson even mentions the presuppositions of questions and imperatives, his account acknowledges only statement-presupposers.  He does not give a general account of presupposition that would handle question-presupposers and imperative-presupposers as well as statement-presupposers.  This is a serious defect in his account.  Based on his position that referring expressions within statements can have presuppositions, he can be forced to admit that questions and imperatives also can have referring expressions within them that presuppose.  His account would have to admit that the question "Did the present king of France go bald?" carries the same presupposition as the statement "The present king of France is bald".  Even if he were prepared to admit this point, though, his formal account of presupposition leaves no logical room for it.  How could we possibly plug a question into the "S" position of the dual entailment model of implication that defines the presupposition relation?  How could the presupposition of the question about the king of France really be a truth-value condition of that question?  A question does not seem to be the kind of thing that has a truth-value, even when it is well-formed and successful as a question.
 

Another example of problematic bias toward statements is that the Strawsonian account acknowledges only statement-presuppositions.  But presuppositions seem to come in other forms as well, such as in the form of concepts.  Kant argued that there are a priori concepts presupposed in our experience and thought and knowledge.²³  Even Strawson recently acknowledged that concepts can be presuppositions.²⁴  Some philosophers would go further and maintain that even precepts can be presuppositions, i.e., that some presuppositions are in the form of an imperative.
 

More generally, Strawson's account takes only linguistic acts, such as statements, to have presuppositions.  It does not acknowledge presuppositions of mental states such as beliefs, presuppositions of mental acts such as acts of judging or doubting or reasoning, and presuppositions of behavioral acts.  Even if we apply only the Strawsonian criterion that a presupposition governs both its positive and negative presupposers, other states and acts carry presuppositions.
 

For example, a belief presupposes, whether stated or unstated.  The statement "The present king of France is bald" presupposes the truth of the claim that there is a present king of France.  But to accept a statement is at least one way to form a belief.  So, if someone accepts that statement-presupposer, she forms a belief that the present king of France is bald.  Her belief presupposes the truth of the claim that there is a present king of France--as does the negation of her belief-presupposer.  If the presupposition failed, because the presupposed claim is false, neither the positive nor negative belief-presupposers would make much sense as beliefs.  Neither could be fully well-formed beliefs; neither could succeed as beliefs.
 

Just as beliefs have presuppositions, so do mental acts.  Descartes' "cogito, ergo sum" is, arguably, an argument that mental acts, including doubting, presuppose a thinking subject of such states.  Somewhat similarly, Kant argued for a transcendental unity of apperception, a self that is presupposed by acts of judging and thinking and experiencing.  Consider some ordinary cases of mental acts.  To doubt that there are (or are not) any cars in the parking lot on weekends presupposes, among other things, that one is committed to the existence of cars and parking lots.  If one of these presuppositions fails, one's doubt no longer makes much sense.  It would no longer be fully well-formed as a doubt; it would no longer succeed as an act of doubting.  To judge that one ought (or ought not) to row presupposes the truth of the claim that one is able to row, on the principle that "ought" implies "can".  If one is not able to row, then one's judgment that one ought to row would not make sense.  It would not be fully well-formed as a judgment; it would not succeed as an act of judging.  Behavioral acts, as well, seem to have presuppositions.  John's act of going (or not going) to the store presupposes the truth of the claim that there is a store.  If there is no store for him to go to, it would not make much sense for him to go to it.  It would be poorly-formed as an act; it could not possibly succeed as an act.
 

Even restricting attention only to statements, Strawson faces damaging criticism.  According to Romane Clark, Strawson fails to distinguish between "presuppositions which act as linguistic prerequisites to meaningful expression at all...[and] those which act as conditions which must be fulfilled before the presupposing statement can be judged either true or false."²⁵  In other words, there seem to be different levels of presuppositions: lower-level ones and higher-level ones.  Even if some lower-level presuppositions are only truth-value conditions, other more fundamental presuppositions seem to be conditions of meaningful expression in the first place.²⁶
 

So, the Strawsonian account of presupposition has significant problems.  Nevertheless, it brought together into a neat package a number of valuable insights about presupposition.  We can build on these insights and establish a more adequate account.  For example, we have good reason to agree with Strawson that a presupposition is not a truth-condition but rather some unusual kind of condition.  The best that Strawson could do was to point out that a presupposition is a condition of the success of a statement, that a presupposition is a condition of a statement being well-formed.  Furthermore, we have good reason to agree with Strawson that "presuppose" picks out not an act but a relation, and more particularly, that the presupposition relation is a logical relation and is in some sense a relation of implication.²⁷
 

A presupposer carries a presupposition by implying it; a presupposition governs a presupposer(s) as a background implication.  One's commitment to a presupposer commits one to its presupposition(s) out of logical necessity. Now we need to avoid a further confusion.  The presupposition relationship is not the standard implicative relationship of logical entailment.  The two differ in many ways.  A presupposition governs both positive and negative statement-presupposers.  If p presupposes q, ~p presupposes q.  On the contrary, for any p and q, if p entails q, the negation of p need not entail q.²⁸  Modus tollens is valid for entailment, but not for the presupposition relation.²⁹  The entailment relation can be reflexive or symmetrical and transposition holds (usually uncontroversially).  The presupposition relation cannot be reflexive, seems not to be symmetrical, and is not transposable.³⁰  The presupposition relation carries an element of dependency or priority that is unidirectional.  A presupposer is dependent on its presupposition; the presupposition is in some sense logically prior to its presupposer(s).³¹  More generally, entailment is usually thought of as a truth-functional and therefore truth-conditional relationship.  But the presupposition relationship is not even truth-conditional, much less truth-functional.
 

Philosophers too often automatically take logical implication to be the relationship of formal logical entailment, thereby confusing presupposition and entailment, often with bad consequences.³²  For example, those who interpret "'ought' implies 'can'" as "'ought' entails 'can'" miss the logic of the implication involved.  Not only does 'ought' imply 'can'; 'ought not' implies 'can'.  We would work ourselves into all kinds of logical fits trying to employ the logic of standard entailment here.  The logic of presuppositional implication, though, fits this case well.  'Ought' implies 'can' by presupposing 'can'.³³
 

A presupposition is a logically necessary yet prior condition.  But what sort of condition?  Not a truth-condition.  Nor a truth-value-condition.  Some presupposers, such as questions, are not truth-valued.  Also, the Strawsonian account defines presupposition as dual entailment, and ordinarily we think that entailment holds only between successful statements (true or false).  But even a statement-presupposer with a false presupposition carries its false presupposition.  How could "The present king of France is bald" presuppose "There is a present king of France", if the presupposition's falsity makes the presupposer a "pseudo-statement"?  How can pseudo-statements stand in entailment relationships?  Can a pseudo-statement such as "Cautious triangles squabble solidly" entail anything?  We need to break from the Strawsonian account more radically.

John Post, in a position somewhat similar to Strawson's, contends that "a presupposition is best construed as a necessary condition of the proper performance of an act" (including speech acts).³⁴  He offers this example: If one tries to state that the king is bald, then if there is no king, one cannot succeed at performing this act.³⁵  Post's account is helpful but inadequate.  Mental states, as well as acts, can have presuppositions; we speak of presuppositions of dispositional states such as beliefs.  Wilma's belief that Fred has stopped forging checks presupposes the truth of the claim that Fred once forged checks.  But one does not perform a belief, so Post could not speak of the proper performance of a belief.  In general, states form and exist.  Post's position might be modified accordingly: a presupposition is a necessary condition of the proper performance of an act or proper formation of a state.
 

The sort of propriety-condition Post has in mind here, though, is not an ordinary one.  Ordinarily, an act is proper or improper if one may or may not perform it, or perform it in a certain manner, given the circumstances.  For Post, a presupposition is a propriety-condition by being a performance-condition, and therefore a possibility-condition, of the act.  If there is no king, and Smith says that the king is bald, then the false presupposition prevents Smith's utterance from being the act of stating that the king is bald.³⁶
 

Nicholas Rescher, too, thinks that one kind of presupposition is a possibility-condition.  A statement can be impossible, he says, by being improper and thus meaningless: "(The meaningfulness of the sentence) 'The dog x-y-z the man' presupposes (that) 'The dummy-expression "x-y-z" stands for a verb.'"³⁷  If "x-y-z" is not a verb, Rescher notes, the statement fails as a statement; it is neither false nor impossible to utter--but meaningless.  Unfortunately, Rescher mentions this "meaning presupposition" only in passing.³⁸
 

From Strawson, Post, Rescher, and others, we have the basis of a more adequate account of presupposition.  Denial of a presupposition in some way undermines the well-formedness of a presupposer.  A presupposer with a failed presupposition is not well-formed and therefore cannot possibly succeed as the kind of thing it is: as a belief, a statement, a question, an imperative, a command, an act of judging or doubting or knowing or experiencing, or a behavioral act.³⁹
 

Let us consider briefly what is meant by a presupposer of any kind being well-formed or poorly-formed in the way we are using those terms.  We are familiar with the idea of a linguistically articulated statement being well-formed or poorly-formed.  For example, such a statement can be semantically well-formed or not: "Snarks wither calubirously" has some semantic components that are not individually meaningful; they do not form a meaningful statement.  Indeed, the statement is so poorly-formed as to be mere gibberish.  A statement can be also be grammatically poorly-formed.  "The dog bite the cat" does not make much sense and fails as a meaningful statement, but it is more well-formed than gibberish; we can easily grasp its grammatically well-formed counterpart "The dog bit the cat".  "Cautious triangles squabble solidly" may pass syntactical muster, and its semantic components are individually meaningful, but its components still fail to form a meaningful, literal statement in any context.  "The round square was clearly visible on the blackboard" is also in many ways well-formed; it is poorly-formed only because one of its terms is self-contradictory.
 

Now, what about the statement "The present king of France is bald", in the context in which there is no king of France?  It is grammatically well-formed, its semantic components are individually meaningful, its terms are self-consistent, and there are alternative contexts in which it would be a fully meaningful, literal statement.  In the given context, it is even well-formed enough to be expressible and to stand in logical relationships with other statements.  However, in that context, something has gone wrong with it.  Remember, the offending statement is neither true nor false, for our earlier analysis showed that a statement with a failed presupposition has no truth-value at all.  Something about the context of the statement has undermined it as a fully well-formed statement.  The statement fails to be fully well-formed because one of its presuppositions fails.  The presupposition is a framework commitment governing whether the statement is well-formed.  Lacking that presuppositional framework, the statement-presupposer fails as a statement and in that context is meaningless.  It is in this specific sense that I suggest we can understand a presupposition as a meaningfulness-condition of its presupposer(s).
 

An undermined presupposer is not thereby mere gibberish; it is not simple nonsense, completely unintelligible.  We need to recognize that there are different levels of meaninglessness.  J. L. Austin, commenting on the statement, "John's children are all bald", when its presupposition that John has children fails, puts it this way:

A presupposition can best be understood, then, as a necessary condition of the meaningfulness of its presupposer(s).⁴²  Modifying Post's account, we may conclude that a presupposition is a necessary condition of a presupposer state or act being fully well-formed, thus successful--and in this sense meaningful.
 

There is considerable confusion about what counts as a presupposition.  Strawson and Post both point out that the statement "The king of France is bald" presupposes the external fact that there is a king of France.⁴³  On the contrary, I am contending that the presupposition is not the brute fact obtaining in the world but instead is the logical commitment to the truth of the claim.  One's statement that the present king of France is bald presupposes, among other things, the truth of the claim that there is a king of France.  One's statement does not presuppose the fact that makes the claim true.  Is this a distinction without a difference?  After all, if a statement-presupposer such as "The present king of France is bald" is true, it would seem to follow that as a matter of fact there is a king of France.  This last point is true enough, but there is a real distinction between the true commitment and the fact that makes the commitment true.⁴⁴
 

It would be odd indeed if the presupposition relationship, which we have characterized as a necessary logical relationship, could hold between a belief and a brute fact.  If it could, then we would be led to a bizarre conclusion: a presupposer could be undermined by some fact in the world independent of the presupposer.  What could the necessary connection be between presupposer and presupposition?  Causal necessity?  Physical necessity?  It seems reasonable to think that the sort of necessity at work is logical and that a presupposer can be undermined only by some other commitment one has or could have, for our commitments are connected logically and semantically.
 

Furthermore, for those who hold that a presupposition is a possibility-condition, such as Post, Rescher and some others, a fact or event surely cannot be a presupposition.  If the fact did not obtain or the event did not occur, then the presupposer would not be possible.  But this view falls by counterexample.  Consider Billy Graham, who believes that a guardian angel saved him, and whose belief therefore presupposes that angels are real.  If this presupposition is a matter of the world being a certain way, and if the world is not this way--if angels are not real--then Graham's belief is not possible.  But according to his own avowal, Graham clearly does have this belief, so it certainly is possible.  Furthermore, his belief is at least well-formed enough for him to be able to express it, for others to be able to understand it, and for his belief to stand in logical relationships with not only other beliefs of his but beliefs of other people.  Nevertheless, his belief does presuppose the truth of the claim that angels are real.  Given that his presupposition fails, the belief is not fully well-formed and therefore cannot succeed as a belief.⁴⁵
 

Our account of presupposition extends to presupposers that are not statements, such as behavioral acts, mental acts, and mental states.  These other kinds of presupposers are structured in ways that are well-formed or poorly-formed, too.  For example, if Sarah is told that the present king of France is bald and accepts that statement, she forms a belief that the present king of France is bald.  And of course she can express her belief in the form of a statement.  Whether one moves from belief to statement or vice versa, the statement and corresponding belief have the same semantic content and logico-grammatical form.  If the statement she accepts has the form of a counterfactual conditional, her corresponding belief does too.  If the statement she accepts has the form of a universal, her corresponding belief does too.  And the corresponding belief has the same logical properties of the statement.  If the statement is self-consistent (or self-contradictory), the belief is too.  So, there are reasons to conclude that if the statement is poorly-formed, then the corresponding belief is poorly-formed.  A poorly-formed belief fails, either partially or fully, as a belief; it is neither true nor false.  One way that a presupposer can be poorly-formed is by having a failed presupposition.  It makes sense to say that Sarah's belief that the present king of France is bald (in the context of there not being a king of France) is poorly-formed and therefore meaningless due to presupposition failure.
 

Or consider a behavioral act.  Sarah's act of going to the store embodies her intention to go to the store.  Just as to accept a statement is to form a belief, to accept an imperative (such as a command or value judgment) is to form an intention.⁴⁶  The intention, in imperative form, defines and structures the act, which is why we identify and individuate actions primarily by their constitutive intentions and not by their physical features or consequences.⁴⁷  The imperative can be well-formed or not, as we noted earlier in an example about rowing; therefore so can the intention and the act.  If no store exists, Sarah's intention to go there is poorly-formed and so she cannot succeed at going to the store.  The act is not well-formed; it is not meaningful as an act.
 

An account that explicitly presents a presupposition as a necessary meaningfulness-condition explains all of the features of presupposition we have so far elicited.  A presupposition is not an assumption or supposition or presumption; these conceptual relatives do not locate meaningfulness-conditions.  To presuppose is not to act; presupposing is not something one actively does.  One cannot presuppose and then reason forward from the presupposition; one can reason forward from acts of assuming, supposing and presuming.  To presuppose is to logically imply.  But the presupposition relationship is not that of entailment, for reasons already given.
 

A presupposition is not a truth-condition, nor a truth-value condition.  With regard to statements (and beliefs), we could say that a presupposition functions a fortiori as a truth-value condition.  But this is because a presupposition is a more fundamental kind of condition, as a necessary condition of a statement being fully well-formed and thus successful--and therefore meaningful--as a statement in a context.
 

We can now explain why a presupposition governs both a statement presupposer and its negation.  If a statement is meaningful as a statement, so is its negation; if it is not meaningful, neither is its negation.  But so, too, for questions, for commands, for beliefs, and for other kinds of presupposers.  The acts of continuing to play chess with Spassky and not continuing to play chess with Spassky both presuppose that one played chess with Spassky.  A presupposition governs its positive and negative question-presupposers or concept-presupposers or command-presupposers or act-presupposers, not merely positive and negative statement-presupposers.⁴⁸
 

Our account of presupposition does not bias us toward statements, unlike the Strawsonian account.  Rather, all of one's mental states and mental acts, linguistic acts, and behavioral acts carry logical implications in the form of presuppositions.  These presuppositions provide the contexts in which our mental states and all of our kinds of acts can be meaningful.  We have logical room for admitting not only presupposers other than in the form of statements but also presuppositions other than in the form of statements.  A concept, for example, could function as a meaningfulness-condition.  On this account we are not straight jacketed into an entailment model that would explain only how statements could be presuppositions.  If a presupposition fails (e.g., a statement-presupposition turns out to be false or a concept-presupposition turns out to be poorly-formed), any presupposer it governs will in that context be meaningless, but not utterly nonsensical.  So, we can account for why a failed presupposition so fundamentally undermines its statement presupposers: If a presupposer statement is rendered meaningless by not being well-formed enough to succeed as a statement (in that context), then it cannot have a truth-value.  And we can also account for why one answers a question whose presupposition fails, such as "Have you stopped forging checks?", by challenging the presupposition and denying that the apparent question is meaningful in that context: "Your question makes no sense; I never forged checks."
 

What about the last question we posed for Strawson?  How can a presupposer with a failed presupposition stand in the logical relationship of presupposition?  The version of this question relevant to our position is this: How can a meaningless presupposer still have a presupposition?  The meaningless presupposer may still be partially well-formed, or it may be so poorly-formed that it is utter nonsense.  In either case, though, the presupposer implies its presuppositions as conditions of its meaningfulness.  The conditions apply to the presupposer whether it is meaningful or not.⁴⁹
 

Another feature of presuppositions now becomes clear.  Assumptions and conclusions are both part of whatever subject is under consideration.  But shifting from a presupposer to its presupposition changes the subject.  For example, modern science is concerned with which physical objects occur and with their features and relationships, but in so doing science presupposes that there are physical objects.  To ask if physical objects are real--even to discuss the issue of their reality--is to step outside of science.  Many would say that attending to this presupposition is no longer a scientific but a philosophical concern.  And if physical objects were not real, scientific statements that describe, predict and explain them would be meaningless.⁵⁰  This makes sense if the presupposition is a meaningfulness-condition.
 

On this account of a presupposition, we have logical room for Clark's point that there are various levels of presuppositions.  Some presuppositions are very simple and low-level; they govern a limited context within a conceptual system.  For example, "Fred once forged checks" may govern only a limited range of questions such as "Has Fred stopped forging checks?" and a limited range of statements such as "Fred continues to forge checks."  Other presuppositions, however, govern an entire conceptual system.  Kuhn speaks of "paradigms" that limit possibilities and limit what can be meaningful for an entire area of scientific activity.⁵¹  Toulmin notes that Kuhn's paradigms have the status of high-level presuppositions, which he calls "ideals of natural order".⁵²  Harold I. Brown speaks of "paradigmatic propositions" that "state fundamental presuppositions which control scientific research in a given era."⁵³
 

We can also make sense of reasoning back to presuppositions.  We can locate those conditions of the meaningfulness of a presupposer by reasoning back to them.  We can ask, "what does a given presupposer necessarily imply for it even to be meaningful?"  The unidirectional dependence or priority that marks the presupposition relationship now makes sense.   A presupposition is a commitment that is logically prior; commitment to a presupposer logically implies commitment to its presuppositions on pain of deep logical absurdity.  Commitment to a presupposition provides (at least part of) the needed logical framework within which commitment to its presupposer can meaningfully take place.  This is why we can reason backward to a presupposition, but not in the manner of an assumption.  Assumptions are premises in our reasoning; a presupposition is a much more deeply placed commitment.  We may reject a premise and seek a different route to its conclusion.  We cannot reject a presupposition without rejecting as meaningless all the presupposers it governs.
 

A presupposition is not only a condition of the meaningfulness of its presupposer, but also a condition of our being able to think through that presupposer, and ultimately a condition of the presupposer presenting a possibility for us.⁵⁴  If we reject a presupposition, then the content of any of its presupposers cannot present a possibility.  Say we deny that Fred once forged checks; then we must deny the possibility that Fred has stopped forging checks.  But to reject a presupposition undermines all of its presupposers, so we must also deny the possibility that Fred has not stopped forging checks.  Neither presupposer presents a possibility; neither is meaningful in the context of our rejection of the governing presupposition.
 

Presuppositional reasoning takes two related forms.  We may find we accept a given presupposition; then we can reason to what possibilities this presupposition necessarily commits us to, since all of its presupposers present possibilities to us (some presupposers, of course, may fail in other ways, such as by being false).  Alternatively, we may find that we accept the meaningfulness of some possibility; then we can reason from this presupposer to its governing presupposition(s), to which we are necessarily logically committed.
 

Some philosophers question the legitimacy of reasoning to presuppositions because presupposers are so intimately dependent on their presuppositions.  Humphrey Palmer's account of presuppositional reasoning is an example.  Say that we try to reason from a presupposer to its presupposition.  The problem, according to Palmer, is that "the presupposed constituent...[is] needed at the outset, to ensure the propriety of the item presupposing it."⁵⁵  Palmer thinks that a presupposition is needed for its presupposer even to be proper (much less true or false), but he argues that one cannot discern the propriety of a presupposer without determining its presuppositions.⁵⁶  In this way the presupposer already appeals to its presupposition, so that the presupposition cannot independently be derived from the presupposer.  If one can establish a premise, then one has already had to establish its presupposition(s), and so it would be simply circular then to derive any of its presuppositions from the initial premise.  He concludes that for most purposes arguments of this sort are objectionable because circular.⁵⁷  As Palmer notes, the issue here is not whether the premise can be true without the conclusion being true too, for "in any valid argument the premisses can't be true unless the conclusion is [true]...."⁵⁸  The issue is whether one can know that the premise is true without knowing already that the conclusion is true.  Can we establish the premise independently of the conclusion?  This is an epistemic concern.⁵⁹  Palmer does not see how one could know that a premise is even proper, much less true, without already knowing that its presupposition is true.
 

On our account of presupposition, no epistemic circularity arises.  One can be committed to and aware of some presupposer without being aware of one's necessary commitment to its presupposition.  Moving from the presupposer to the presupposition is often a discovery process.  The idea that we can make this sort of discovery is not news.  We all have to discover at least some of our commitments.  For example, we learn that the very meaningfulness of one of our beliefs commits us necessarily to some other belief.  Or we learn that the very meaningfulness of some statement we have made commits us necessarily to some further statement.  We may not have realized that we had the presupposed belief or statement, or we may simply not have grasped the logical connection between our beliefs or statements.  We discover an implication we did not realize earlier.  So, in moving from a presupposer to its presupposition, there is nothing circular or objectionable.⁶⁰  Presuppositional reasoning reveals what we did not realize we were committed to but must be committed to--given that we find some presupposer meaningful.  The form of reasoning is dialectical ad hominem.⁶¹  One can employ it on oneself or others.  Its most powerful use is in a more abstract and formal way, when one argues that anyone who is committed to p must be committed to q, i.e., that p presupposes q.⁶²
 
 

Basic presuppositions are the business of philosophy.⁶³  Not surprisingly, philosophy traditionally has employed both forms of presuppositional reasoning.  Much philosophy proceeds by showing the consequences of rejecting a presupposition, a negative version of presuppositional reasoning.  Notice how Berkeley attacks Locke and the emerging materialistic philosophy of the early modern era.  Essentially, he argues that the meaningfulness of concepts of physical objects presupposes our knowledge of such objects.  But, he contends, given the nature of sensory experience, we do not--indeed cannot--have such knowledge.  So, concepts of physical objects are meaningless.⁶⁴  As Grayling understands Berkeley, "what it does not make sense to talk about is what cannot be met with in the world....The modality is to be taken seriously here; what on these terms is inconceivable, that is, does not make sense, is impossible."⁶⁵  Hume uses much the same sort of reasoning against the idea of a substantival self.  Though Berkeley and Hume do not cast their accounts explicitly in terms of presuppositions, they appeal to them nonetheless.  Kant speaks explicitly of certain presuppositions that function as conditions of the possibility of experience and knowledge.  He, too, is concerned to point out ways of thinking and ways of reasoning that are meaningless due to presupposition failure.
 

In the history of philosophy, argument to presupposition has been used to ferret out commitments that are more and more fundamental.  Arguably, this has been the dominant form of philosophical reasoning.  Traditionally, much of philosophy worked to reach absolutely fundamental commitments.  True, philosophers did not begin to identify these commitments as presuppositions until later in history; the concept of presupposition was not even developed until the late medieval era.⁶⁶  Nevertheless, even when philosophers have not been fully clear about what they were doing, the kind of fundamental commitments philosophers have tried to locate sound something like presuppositions, and the way philosophers have elicited and established these commitments sounds something like argument to presupposition.
 

Pre-Socratic philosophers argued to the necessary conditions of the intelligibility of aspects of the world, such as plurality, change, and so forth.  Plato, too, argued in this manner, maintaining that "change itself is intelligible and possible only if there exist entities which are not themselves involved in the change."⁶⁷  Plato essentially contends that the meaningfulness of our ordinary commitments to objects in a realm of becoming commits us necessarily to the Forms.  Socrates and Plato speak of a dialectical process of thought which "goes from hypotheses to beginnings".  Plato offers little by way of explicit analysis of philosophical method.  One commentator suggests that "One might almost suppose that Plato thought it obvious how you did it, or that he thought his readers would no more expect an explanation than a cook expects the recipe-book to tell her how to boil water."⁶⁸  Aristotle was more explicit:

One of the main tasks of philosophy is to determine which presuppositions can be consistently rejected.⁷⁰  We could easily reject some of our low-level presuppositions, if we accept that their presupposers are meaningless.  We could even reject higher-level presuppositions such as one within science, if we reject as meaningless the scientific conceptions, descriptions, explanations, and theories relying on it.  The history of science contains fascinating examples of presuppositional shift.⁷¹  But is the philosophical tradition correct?  Are there yet higher presuppositions that govern every conceptual system and that are so fundamental that they cannot be rejected on pain of self-inconsistency?
 

I can only sketch an answer here. I would argue that our most basic human powers and activities carry presuppositions.  Knowing, thinking, acting, experiencing, reasoning, and the like are meaningful only within certain presuppositions.  To reject one of these presuppositions would undermine something so basic to our humanity that we could no longer be functional persons.  But we could not succeed at undermining our personhood.  The attempt to reject basic presuppositions itself presupposes them and is self-defeating, self-undermining.  They are undeniable bedrock commitments common to us as humans.⁷²
 

Briefly consider rationality.  When we reason, in any mode of reasoning, we presuppose the concept of evidence--of one point making another point (more) worthy of acceptance.  This presupposition is not a premise or conclusion in our ordinary reasoning.  It is needed for reasoning to be a meaningful activity.  If we try to reject this concept of evidence, any grounds for the rejection will presuppose the very concept of evidence we are attempting to reject.
 

We can argue to fundamental presuppositions, and for or against them, using dialectical ad hominem arguments, especially transcendental arguments.  Some philosophers have spoken of categorial commitments, commitments to concepts and principles so fundamental that they reveal inescapable commitments about ourselves and the world.  I believe that categorial commitments have the status of fundamental presuppositions, so that it makes sense to speak of categorial presuppositions.  The search for these presuppositions is central to philosophy; they are involved in every philosophical problem we identify and are one objective cornerstone of a world view.  But we will not make progress in this search without understanding the nature of presupposition.
 

Dr. Seth Holtzman
Catawba College
 
 

1I presented an earlier and shorter version of this paper in front of the following audiences: the 1997 Southern Society for Philosophy and Psychology in Atlanta, where it won the SSPP's Richard M. Griffith Memorial Award; the Spring 1996 Kentucky Philosophical Association at Eastern Kentucky University in Richmond, KY; Murray State University in Murray, KY in April 1996; the 1996 Intermountain Conference at Western Carolina University in Cullowhee, NC; and the 1996 Tennessee Philosophical Association at Vanderbilt University in Nashville, TN. I would like to thank E. M. Adams, Terry Foreman, Tom Olshewsky, Curtis Bridgeman, John Post, Donald S. Lee, Nancy Simco, Jack Weir, and various participants for their helpful comments and criticisms of that paper.

²The Philosophy of P. F. Strawson, ed. Lewis Edwin Hahn, The Library of Living Philosophers, Volume XXVI (Chicago and LaSalle, Ill: Open Court Publishing Company, 1998).

³For Peter Strawson's general account, see "On Referring" Mind 59 (1950), esp. pp.329-33; Introduction to Logical Theory (London: Methuen & Co., 1952), esp. p.175, "A Reply to Mr. Sellars", The Philosophical Review 63 (1954), as well as Meaning and Truth (Oxford: Oxford University Press, 1970).

⁴Presupposition, Janua Linguarum, series minor 203(The Hague: Mouton & Co., N.V. Publishers, 1974), p.7.

⁵For example, consider the position Ernest Sosa found himself in. After giving what he takes to be a persuasive account of how empirical knowledge relies on presuppositions, he ended in confusion:

⁶We need to clarify both the noun and verb forms: How should we understand what a presupposition is, and how should we understand "p presupposes q"?

⁷Under the headings, "presuppose" and "presupposition", we find the following definitions (the underlining is mine):

To presuppose is to suppose, lay down, or postulate beforehand; hence, to take for granted or assume beforehand or to start with; to presume....A  presupposition is a supposition antecedent to knowledge; the assumption of the existence or truth of something, as a preliminary to action, argument, etc

⁹See Llewelyn, pp.158-62; also see John Frederic Post, "An Analysis of Presupposing", The Southern Journal of Philosophy 6 (Fall 1968), p.166.

¹⁰Post, "An Analysis of Presupposing", p.167.

¹¹By "backwards" I mean simply that we can reason from our commitments to their precommitments, whatever those precommitments are. We can elicit tacit assumptions, for example, and so discover the reasons we started from in order to reach the conclusions we find ourselves committed to.

¹²I am using "truth-condition" in a more traditional sense than it is ordinarily used these days. I do not have in mind either a possible-worlds account or a Tarskian account of truth. I am closer to Aristotle or perhaps to C. I. Lewis. As I am using the term (and restricting this account for simplicity's sake to sentences), a truth-condition picks out anything independent of a sentence that must hold in order for the sentence to be true. Something that exists or obtains in the world could be a truth-condition of a sentence. I also speak of a sentence being a truth-condition of another sentence; e.g., an assumption can be a truth-condition of a conclusion. I am willing to go further and speak of a psychological state or act being a truth-condition of another such state of act; e.g., a belief can be a truth-condition of another belief. So, something about a sentence or belief--its truth or meaningfulness--can be a condition of the truth of another sentence or belief. I contend that the psychological is real. I place psychological states and acts, as well as linguistic acts and expressions, in the world. So, facts about sentences or about beliefs obtain in the world independently in a way that allows them to be truth-conditions.

¹³A presupposer can have more than one presupposition. In this paper, for the sake of analysis, we will usually mention and focus on only one presupposition of a given presupposer.

¹⁴These examples are derived from points in various philosophical and literary sources and were modified for purposes of this paper.

¹⁵I take sentences and indeed all of language to be meaningful in terms of acts, such as speech acts and mental acts. We sometimes find it helpful to abstract some linguistic unit from its employment in an act and to treat it as an abstraction. Accordingly, I do not draw a hard distinction between someone's particular speech act carrying a presupposition and some sentence or statement or proposition carrying a presupposition. But I reject a Platonist account of propositions; propositions are abstractions. What are real here are mental states and acts, as well as linguistic and behavioral acts, all of which are constituted essentially by a semantic intentionality that (I would argue) is a unique, categorial dimension of reality.

¹⁶See Strawson's "On Referring", esp. pp.329-33, and Meaning and Truth.

¹⁷Bas C. van Fraassen, "Presupposition, Implication, and Self-Reference", The Journal of Philosophy Vol. 65 (March 7, 1968).

¹⁸Robert Stalnaker, "Presuppositions", Journal of Philosophical Logic 2 (1973), p.447. (Underlining is mine.) Examples such as this abound in the philosophical literature. Here are only a few more examples. Duane Whittier says that "All philosophical thought involves making 'basic assumptions', and these assumptions or 'presuppositions' always have the status of being 'essentially-contested concepts' in "Basic Assumption and Argument", The Monist 48 (1964), p.490. In an introductory philosophy book, the authors say, "'presuppose' means to assume or to take for granted the truth of some sentence without explicitly acknowledging or recognizing that fact." This account occurs in Samuel Gorovitz et al., Philosophical Analysis: An Introduction to Its Language and Techniques, 3rd edition (NY: Random House, 1979), pp.66-7. William E. Kennick says, "Some presuppositions are empirical propositions...Such presuppositions we shall call 'material assumptions'." This quote is from "Metaphysical Presuppositions", The Journal of Philosophy 52 (1955), p.769.

¹⁹See Bertrand Russell, "On Denoting", Mind 14 (1905); see also both The Philosophy of Logical Atomism, lectures first published in The Monist: Vol. 28 (1918), pp.495-527; Vol. 29 (1919), pp.32-63, 190-222, and 345-380, and "Logical Atomism" in Contemporary British Philosophy, First Series, Ed. J. H. Muirhead (London, 1924); reprinted in The Philosophy of Logical Atomism, Ed. and with an Introduction by David Pears (La Salle, IL: Open Court Publishing Company, 1985).

²⁰See Strawson's "On Referring" and Meaning and Truth. Actually, Everett J. Nelson seems to have publicly formulated this distinction between assertion and presupposition several years before Strawson. See Morris Weitz's "The Grounds of Sense: The Philosophy of Everett J. Nelson", Philosophy and Phenomenological Review 33 (1946). For an even earlier connection, note the relationship between Strawson's position and that of Gottlob Frege in the following passage from Frege's "On Sense and Meaning" in Translations From the Philosophical Writings of Gottlob Frege, 3rd ed., edited by Peter Geach and Max Black (Oxford: Basil Blackwell, 1980), p.69:

²²Gilbert Ryle makes the same point: "It is neither true nor false to say 'The King of France is not Poincare'." See "Systematically Misleading Expressions", in Logic and Language, First and Second Series, edited with introductions by Antony Flew (Garden City, NY: Doubleday & Company, Anchor Books, 1965), p.29.

²³Some others who agree that a concept can be a presupposition include the following: W. H. Walsh, "Categories", Kantstudien 45 (1954); Bruce Wilshire, Metaphysics: An Introduction to Philosophy, Traditions in Philosophy Series (New York: Western Publishing Company, Pegasus Books, 1969); Everett W. Hall, Philosophical Systems: A Categorial Analysis (Chicago: The University of Chicago Press, 1960); Brand Blanshard, who agrees with Price that "[the use of universals] begins far earlier than the use of words, and indeed that any use of words presupposes it" in Reason and Analysis, The Paul Carus Lectures, 12th Series (La Salle, IL: Open Court Pub. Co., 1964), p.391; and E. M. Adams, The Metaphysics of Self and World: Toward a Humanistic Philosophy (Philadelphia: Temple University Press, 1991).

²⁴In Analysis and Metaphysics (Oxford: Oxford University Press, 1992), Strawson makes the following claim:

A concept or concept-type is basic in the relevant sense if it is
one of a set of general, pervasive, and ultimately irreducible
concepts or concept-types which together form a structure--a
structure which constitutes the framework of our ordinary thought
and talk, and which is presupposed by the various specialist or
advanced disciplines that contribute, in their diverse ways, to
our total picture of the world.

²⁶Wilbur Marshall Urban held a view of this sort. He asks, "Are there not certain ideas...outside the bounds of which it is not possible to think consistently--much less speak intelligibly?" in The Intelligible World: Metaphysics and Value (London: George Allen & Unwin, 1929), p.43.

²⁷Strawson, "On Referring", p.330; and Introduction to Logical Theory, p.175. Others who agree that the presupposition relation is some kind of logical implication include Van Fraassen, "Presupposition, Implication, and Self-Reference"; Trudy Govier, "Presuppositions, Conditions, and Consequences" Canadian Journal of Philosophy 1 (June 1972); W. H. Walsh, "Categories"; Humphrey Palmer Presupposition and Transcendental Inference (NY: St. Martin's Press, 1985); and David Rynin, "Donagan On Collingwood: Absolute Presuppositions, Truth and Metaphysics", Review of Metaphysics 18 (1964-65), pp.302-03.

²⁸Some would say that if q is a necessary truth, then any p entails q. But certainly for contingent truths this is not so.

²⁹Van Fraassen, "Presupposition, Implication, and Self-Reference", p.138.

³⁰Govier, "Presuppositions, Conditions, and Consequences", p.444. Post disagrees, claiming that unlike entailment, which has a trivial and uninformative reflexive, presupposition has a non-trivial and informative reflexive. I side with Govier and think that Post's examples of reflexivity are poor and fail to make his case. See Post, "An Analysis of Presupposing", p.168. Furthermore, in a later article, he claims that the presupposition relation is irreflexive. See "Referential Presupposition" Australasian Journal of Philosophy 50 (1972), p.161. Since this latter article discusses only referential presupposition, perhaps he could claim that there are reflexive non-referential presuppositions. I would still disagree.

³¹Govier, "Presuppositions, Conditions, and Consequences", pp.444-46. Also see Roger Wertheimer's "Conditions", The Journal of Philosophy 65 (1968).

³²Both philosophers and linguists have made this mistake. Linguist Ruth Kempson concludes that "presupposition, as a new logical relation, is in natural language not distinct from entailment" in Presupposition and the Delimitation of Semantics, Cambridge Studies in Linguistics, no. 15 (Cambridge: Cambridge University Press, 1975), p.100. Linguist Dierdre Wilson essentially agrees, in Presuppositions and Non-Truth-Conditional Semantics (London, Academic Press, 1975), see especially p.61. The long list of philosophers includes the following: Roger Hancock, "Presuppositions", Philosophical Quarterly 10 (January 1960), p.74; John A. Barker, "Presupposition and Entailment", Notre Dame Journal of Formal Logic 17 (April 1976), esp. pp. 276-77; G. W. Roberts, "A Problem About Presupposition", Mind 81 (January 1972); and Roger Montague, "Presupposing", Philosophical Quarterly 19 (April 1969).

Before any of these recent accounts, C. I. Lewis analyzed presupposition as entailment and on this basis could not make sense of a traditional conception of the a priori that relied on the notion of presupposition. See his Mind and the World Order (New York: Dover Publications, 1929), pp.200-02. Everett J. Nelson criticizes C. H. Langford for treating implication as entailment and for therefore concluding that a singular proposition has no contradictory. See Nelson's "Contradiction and the Presupposition of Existence", Mind 60 (1946), pp.319-20. Govier makes clear how the exegesis of Kant and the interpretation of transcendental arguments can go awry when presupposition is understood as entailment in "Presuppositions, Conditions, and Consequences", pp.452-53.

³³Palmer Presupposition and Transcendental Inference, p.107. For a nice example of a misstated debating move, see P. D. Shaw's valuable analysis of Mavrodes' argument in Shaw's "Ought and Can", Analysis 25 (1965), pp.196-97. Mavrodes blurs the distinction between presupposition and entailment and therefore thinks he can show that "is" entails "ought".

³⁴Post, "An Analysis of Presupposing", p.168.

³⁵Ibid., p.169. Other philosophers have gone in a similar direction. Palmer holds that a statement whose presupposition fails does not succeed as a statement in the context, in Presupposition and Transcendental Inference, p.43. Everett J. Nelson characterizes presuppositions as conditions of the existence (versus the truth) of propositions in "Contradiction and the Presupposition of Existence", pp.323-24. Max Black contends that an expression whose presupposition fails is not "properly applicable" in "Definition, Presupposition, and Assertion", Philosophical Review 61 (1952), p.539. J. L. Austin says of a statement with a failed presupposition that "the utterance is void" in How To Do Things With Words (Oxford: Oxford University Press, 1963), pp.50-1.

³⁶Ibid., pp.168-69.

³⁷Nicholas Rescher, "On the Logic of Presupposition", Philosophy and Phenomenological Research 21 (June 1961), p.523.

³⁸Post, too, mentions only in passing the possibility of treating a presupposition as a condition of meaningfulness:

³⁹We should note at this point that there is an apparent ambiguity in the notion of a presupposition as a necessary condition of a presupposer being well-formed and thus successful. One, a presupposition might be a condition of the very possibility of a well-formed presupposer. Two, a presupposition might be a condition of the full well-formedness of a presupposer. In this second case, a presupposer with a failed presupposition would be a possible state or act, but one that could not succeed as the state or act it is because it is not fully well-formed. This apparent ambiguity needs to be sorted out, but it is complex and requires extended treatment not appropriate for this paper. I will take up this matter and other related issues in a future paper. Luckily, that treatment is not vital for this paper. For now, I would contend that presuppositions function in both ways: as conditions of a presupposer being well-formed at all and as conditions of a presupposer being fully well-formed. In either case, a presupposition is a necessary condition of a presupposer being fully well-formed, and that is how I analyze a presupposition in this paper.

⁴⁰Austin, How To Do Things With Words, pp.50-1.

⁴¹R. G. Collingwood, An Essay on Metaphysics (Oxford: The Clarendon Press, 1940), pp.25-6. For similar ideas, see Urban's Language and Reality: The Philosophy of Language and the Principles of Symbolism (London: George Allen & Unwin, 1939), pp.647-48; Black, "Definition, Presupposition and Assertion", p.539; Rynin, "Donagan On Collingwood: Absolute Presuppositions, Truth and Metaphysics", p.326; John Kekes, "Metaphysics and Rationality", Idealistic Studies 2 (May 1972), p.144; and Walsh, "Categories", p.274. Of course, this position has some similarity to Kant's as well. See also Everett W. Hall, Philosophical Systems: A Categorial Analysis; and E. M. Adams, The Metaphysics of Self and World: Toward a Humanistic Philosophy.

⁴²P. T. Geach argues that a presupposer with a failed presupposition is "out of place". The only reason that he refuses to characterize the presupposer as meaningless is because he thinks that "the word ['meaningless'] is a mere catchword nowadays." See "Russell's Theory of Descriptions", Analysis 11 (1950), p.85. Unfortunately, the logical posivitists used the charge of meaninglessness to intellectually discredit entire sectors of discourse, inquiry, and the culture on the basis of a puritanical empiricism. That should not deter philosophers from determining the defensible boundaries between the meaningful and the meaningless and to use the term "meaningless" in philosophical inquiry.

⁴³Indeed, our ordinary discourse about presuppositions provides some support for Strawson and Post, as many of the initial examples of presuppositions employed in this paper reveal.

⁴⁴One problem with couching our account in terms of commitment to a presupposition is that this way of speaking suggests to some people a higher degree of acceptance of a presupposition and of a presupposer than we here intend. Some might think that a presupposition is implied only by a presupposer to which one is firmly committed and that a presupposition is a firm commitment as well. On the contrary, a presupposition is a commitment only in the sense of being a logical implication. And one need not be fully committed to a presupposer. When one proposes an idea, formulates a hypothesis, entertains a plan, or supposes something, one need not have any firm commitment to the idea, hypothesis, plan or supposition. One can entertain and explore possibilities without accepting them. Perhaps we would say that one is committed to the idea or hypothesis or plan or supposition as a possibility--or that it is a tentative commitment. But the point is that one can consider and reason about ideas one has not (fully) accepted and may never accept. Furthermore, one can entertain an idea and by this means explore its presuppositions, again without ever coming to be committed to those presuppositions. Philosophers often explore the positions of other philosophers and ferret out the presuppositions of those positions in order to evaluate the positions. In this way we might speak of a presupposition relying on not a person's commitments but what one would be committed to if one adopted the position. Nevertheless, we will continue to speak of a presupposition as a commitment and trust that no confusion will arise.

⁴⁵We have been speaking of the truth of a presupposition, which suggests that presuppositions come only in the form of statements or beliefs. If presuppositions can take the form of concepts and/or precepts, then presuppositional commitment might be to the well-formedness of a concept or to the validity of an imperative. So, I prefer to speak more generally of the success (or failure) of a presupposition.

⁴⁶E. M. Adams, Philosophy and the Modern Mind: A Philosophical Critique of Modern Western Civilization (Chapel Hill, NC: The University of North Carolina Press, 1975; reprinted, Lanham, MD: University Press of America, 1985), pp.98-9.

⁴⁷See, for example, R. G. Collingwood, The Idea of History (Oxford: Oxford University Press, 1956), pp.213-14; Charles Taylor, Human Agency and Language, Philosophical Papers I (Cambridge: Cambridge University Press, 1985), pp.194ff.; and Richard Taylor, Action and Purpose (Englewood Cliffs, NJ: Prentice-Hall, 1966), p.141.

⁴⁸I realize that some will find my position to be curious. But I do not subscribe to the widespread view that the logical dimension is distinct from the psychological and the behavioral dimensions. I take logical properties to be real and to hold among states and acts with a semantic dimension, whether mental states, mental acts, linguistic acts, or behavioral acts. The logical, as I understand it, is not simply a linguistic matter but primarily a psychological matter. Nevertheless, I contend that this position does not psychologize logic in a way that would undermine the objectivity of logic.

⁴⁹The logic of presupposition clearly takes us beyond a truth-functional or even truth-conditional conception of logic. But I would contend that modern logic is too narrow to suit our needs. There are good reasons to believe that the dominant Principia-inspired conception of logic was developed within a naturalistic philosophy that is biased towards atomism and extensionalism. We should be more suspicious than we are of the philosophical biases built into modern logic.

⁵⁰A phenomenalist might claim that the reduction of physical object language to a sense datum idiom would eliminate our commitment to physical objects but would still allow our continued commitment to physical object language for the purposes of doing science. Most philosophers now reject this reduction; but even if it were possible, nothing but pragmatic convenience would prevent the elimination of physical object language, especially in science. If physical objects are logical constructions out of sense data, then our concern with them is only as logical constructions.

⁵¹Thomas S. Kuhn, The Structure of Scientific Revolutions, 2nd edition, enlarged (Chicago: The University of Chicago Press, 1970).

⁵²Stephen Toulmin, Foresight and Understanding: An Enquiry into the Aims of Science, Foreword by Jacques Barzun (New York: Harper & Row, Harper Torchbooks, 1961), pp.54-5. Also see other works of his: "Does the Distinction between Normal and Revolutionary Science Hold Water?", in Criticism and the Growth of Knowledge, ed. Imre Lakatos and Alan Musgrave (Cambridge: Cambridge University Press, 1970), p.40; "Conceptual Revolutions in Science", in A Portrait of Twenty-five Years: Boston Colloquium for the Philosophy of Science 1960-1985, ed. Robert S. Cohen and Marx W. Wartkofsky, Boston Studies in the Philosophy of Science (Dordrecht: D. Reidel Pub. Co., 1985), p.65; "Conceptual Change and the Problem of Relativity", in Critical Essays on the Philosophy of Collingwood (Oxford: Clarendon Press, 1972), p.205; and "Ideals of Natural Order", reprinted in Scientific Knowledge: Basic Issues in the Philosophy of Science, ed. Janet Kourany (Belmont, CA: Wadsworth Pub. Co., 1987. His position has also been worked out in several books.

⁵³Harold I. Brown, "Paradigmatic Propositions" American Philosophical Quarterly 12 (1975), p.85.

⁵⁴Govier agrees that a presupposition is a possibility-condition of its presupposer, and she uses her account of presupposition to interpret both Kant and Strawson. See "Presuppositions, Conditions, and Consequences", pp.452-56. We often think of possibilities only in terms of states of affairs, in which case we think that only statements and beliefs present possibilities. But in a sense a concept can denote an impossibility ("round square") or a possibility ("plant"). Even a command can be possible to meet or not; what is commanded can be possible ("Read that book") or impossible ("Run the mile unassisted in 2 seconds"). And an act is possible ("running to the store") or not ("running to the moon") and in this sense can present a possibility or impossibility.

⁵⁵Palmer, Presupposition and Transcendental Inference, p.84.

⁵⁶Ibid., p.93.

⁵⁷Ibid., chapter 4.

⁵⁸Ibid., p.30.

⁵⁹Ibid.

⁶⁰Govier says that "To demonstrate that a proposition of the form 'p presupposes q' holds, we must demonstrate not only that p is impossible without q, but also that q is essential for the derivation of p. If this can be done, then q may help to explain or make intelligible the very premise from which it has been derived." See "Presuppositions, Conditions, and Consequences", p.456.

⁶¹There are illegitimate and fallacious uses of ad hominem reasoning, but this way of using ad hominem reasoning is legitimate. It is not designed to mislead or to scare or to avoid logical consequences, but rather to reveal logical consequences in a rational way.

⁶²Of course it is a difficult task. G. J. Warnock is one who acknowledges "the difficulty of becoming aware, at any given time, of the deepest, most unquestioned presuppositions of the day." In English Philosophy Since 1900, 2nd ed. (Oxford: Oxford University Press, 1969), p.118.

⁶³Quite a few accounts of philosophy support this idea; here are some:

1) W. B. Macomber writes that "The history of Philosophy can be read as a constant search for the presuppositions which underlie human experience. It is these presuppositions, rather than the experience which they make possible, which the philosopher calls reality or truth in the highest degree." See his The Anatomy of Disillusion: Martin Heidegger's Notion of Truth (Evanston, IL: Northwestern University Press, 1967), p.20.

2) Robert C. Whittemore writes that "Philosophy today lacks, yet must develop, a methodology for the criticism of its ultimate notions if its progress is not to suffer permanent arrest. As philosophers it is high time that we inquired into the nature of that which is integral to the very structure of any viewpoint, however abstract or concrete. In short, it is time that we looked to the nature of presupposition." See his "Philosophy as Comparative Cosmology", Tulane Studies in Philosophy 7 (1958), p.137.

3) Rescher claims that "there is no denying the more conservative view that at least one of the central tasks of philosophy is to render explicit and to clarify the presuppositions of our...knowledge of the world." See his "On the Logic of Presupposition", p.521.

4) John Kekes contends that "Metaphysical theories are rational and a priori because of fundamental presuppositions. They are the a priori components of metaphysical theories, and they are formulable...." See his "Metaphysics and Rationality", p.138.

⁶⁴For example, Berkeley says, "if what you mean by the word matter be only the unknown support of unknown qualities, it is no matter whether there is such a thing or no, since it no way concerns us: and I do not see the advantage there is in disputing about we know not what, and we know not why." Here he attacks the Lockean substratum account of matter in A Treatise Concerning the Principles of Human Knowledge. See George Berkeley, Philosophical Works, Including the Works on Vision, Introduction and Notes by M. R. Ayers (Totowa, NJ: Rowman and Littlefield, 1980 from the version published in London by J. M. Dent & Sons, Ltd., 1975), pp.100-01. Of course, Berkeley allows that we can talk about tables and chairs; we can use these concepts meaningfully. But these concepts cannot be understood as concepts of physical substances.

⁶⁵A. C. Grayling, Berkeley: The Central Arguments (La Salle, IL: Open Court Pub. Co., 1986), p.36.

⁶⁶Development of the concept of presupposition seems to have occurred in the late medieval era, with some documents showing its appearance, perhaps its first appearance, in Aquinas and Bonaventure.

⁶⁷See H. F. Cherniss, "The Philosophical Economy of the Theory of Ideas", in Plato: A Collection of Critical Essays, Vol. 1: Metaphysics and Epistemology, ed. Gregory Vlastos, Modern Studies in Philosophy (Garden City, NY: Doubleday and Co., Anchor Books, 1971), p.24. Also see Theodore W. Schick, Jr., "How is Philosophy Possible?", International Philosophical Quarterly 31 (June 1991), p.205.

⁶⁸Richard Robinson, "Hypothesis in the Republic", in Plato: A Collection of Critical Essays, p.112.

⁶⁹Aristotle, Metaphysics, Book IV (Gamma), trans. by W. D. Ross, in The Complete Works of Aristotle, Volume 2, The Revised Oxford Translation, Edited by Jonathan Barnes, Bollingen Series LXXI:2, (Princeton, NJ: Princeton University Press, 1984), pp.1587-88.

⁷⁰Rescher claims that "a correct understanding of the nature of presupposition requires the use of modal concepts, [so that] modalities prove to be an indispensable instrument for the explication of philosophically important ideas." See his "On the Logic of Presupposition", p.527. We should note that if presuppositions play a crucial role in philosophy, and if presuppositions involve necessity and possibility in the ways we have argued that they do, then modal terms are critical in philosophical thought. The way that philosophy establishes what is necessary and what is impossible markedly differentiates it from empirical disciplines such as the natural and social sciences.

⁷¹See Toulmin's discussions of "ideals of natural order" in various works, including Foresight and Understanding: An Enquiry into the Aims of Science; The Philosophy of Science: An Introduction, and "Ideals of Natural Order". See also Kuhn's discussions of paradigms in The Structure of Scientific Revolutions.

⁷²In response to Aristotle, we should say that we can be mistaken about even our most fundamental commitments. We can fail to grasp them, and we can misformulate them even if we do grasp them. So, while they are necessary and are already commitments we function with, they are not the "best known" in one important sense.