A Causal Theory of Truth

A Causal Theory of Truth

We have been inundated with causal theories: of perception, knowledge, memory, and reference. But no one (to my knowledge) has proposed a causal theory of truth. On the face of it this is surprising, since truth is so closely bound up with reference. If reference to both objects and properties is subject to a causal theory, why isn’t truth? I will explore a causal theory of truth that seems rather natural, indeed a natural extension of the causal theory of reference. Put simply, the theory says that a belief or statement is true if and only if it is caused by the facts. Some beliefs or statements are caused by the facts and some are not, being caused instead by desires or errors or fictions or fantasies. That is the difference between a true belief and a false belief: its causal relation to the facts. Some beliefs are brought about by objective reality and some are otherwise brought about (say, by subjective factors): to be true is to be caused in the former kind of way. Where the correspondence theory says that truth is correspondence to the facts, the causal theory says that truth is causation by the facts.  [1]

            The theory assumes that the world consists of facts (objects having properties) and that these facts causally shape beliefs, making them true. If it is a fact that p, then it is true that p, so there can be no problem with the theory as far as sufficiency is concerned. But then couldn’t the theory dispense with the causal element and simply equate truth with fact? No: because truth is a property of representations (beliefs or statements or sentences or propositions), so we need something to connect facts with truth. Traditionally that has been a correspondence relation; according to the causal theory, it is a causal relation. For a belief to be true is for it to be caused by a fact, not just for the fact to be a fact: the belief that snow is white is true in virtue of its being caused by the fact that snow is white—that is, the belief is caused by what it represents (what is believed to obtain). In the most straightforward case a person is in perceptual contact with a fact and he or she forms the belief that it is a fact, thus forming a true belief: you see that it’s raining and this fact causes you to believe that it’s raining—so you have a true belief. If you were to be hallucinating rain because of a drug, you might form the same belief but it would be false, since your belief would not be caused by the fact that it’s raining but by the drug. If you dream that p and form the belief that p, then your belief is not true, since it was not caused by the fact that p. If I tell you a lie, my statement is false because it was not caused by the fact I purport to state but by my desire to deceive you; while in the case of a truthful statement a fact causes my true belief and my statement transmits the causal relation to you—you have a true belief because your belief was (indirectly) caused by the fact that I stated to obtain.  [2] When the facts shape belief we have truth, but when illusion, error, deception, and fantasy shape belief we have falsehood. Truth depends on the causal antecedents of belief: do they stem from objective reality or from other factors (often internal to the subject)? Is belief caused by the factual or the fictional?

            That is the simple way to put the theory, but of course it needs to be refined and complicated. Still I wish to emphasize its intuitive starting point: true belief is the kind brought about by the facts; false belief is the kind brought about by things other than the facts. Compare: veridical perception is the kind brought about by external objects; illusory perception is the kind brought about by other factors, such as intoxication or defects of the perceptual system. You believe truly if the facts impress themselves on your belief system; you believe falsely if your beliefs arise from some source other than the facts, such as biases or blind spots. Of course, all factors that influence belief are trivially facts, but truth is having your belief caused by the fact represented by the belief in question. If the fact that p causes you to believe that p, then you have a true belief.

We can compare this account to causal theories of reference.  A speaker refers to an object x with a name “a” if and only if there exists a (suitable) causal connection between x and “a”—say, a chain of causal links leading back to an initial baptism. A speaker refers to a property P with a predicate “F” if and only if instances of P regularly elicit utterances of “F” (or some such). In the case of whole sentences we are dealing with fact-like entities (states of affairs, situations, ways things are) not objects and properties, so these are the appropriate entities to stand in causal relations to sentences.  [3] We simply extend the causal theory from names and predicates to sentences: reference to an object is being caused by that object to utter its name, reference to a property is being regularly caused by instances of that property to utter a predicate, making a true statement is making an utterance caused by an appropriate fact. We thus use the word “true” to distinguish this kind of causation from other kinds—the kinds that produce false statements. To say that a belief or statement is true is to say that it is a consequence of the facts; to say that a belief or statement is false is to say that it is not a consequence of the facts, but of fictions, fantasies, errors, etc. In its strongest form the theory says that the property of truth is that property a belief has when it is caused by a fact (the fact represented). Instead of saying, “Your belief is true” we could equally say, “Your belief is factually caused”.

            At this point a swarm of questions assails the causal theorist; they are for the most part quite familiar. Are the causal conditions necessary and sufficient for truth? How do we handle truths about non-causal facts? What about deviant causal chains? Do facts really cause anything? To spare the reader (and myself) tedium, I will be as speedy as possible with these well-worn issues. Are the conditions necessary? Couldn’t we have true beliefs and yet there be no causal links between belief and fact (pre-established harmony)? What about the truths of mathematics, modality, and morality? Here we can reply by amending the theory from its simple causal formulation: we can invoke the concepts of reason or explanation or counterfactual dependence. Thus: the reason (but not the cause) for forming the belief that p is the fact that p; the explanation for believing that p is the fact that p (where this is not causal explanation); a person would not believe that p were it not for the fact that p. We just weaken the causal relation to accommodate the awkward cases—just as we have to for causal theories of reference and knowledge. The causal theory of truth is thus no worse off than these causal theories (no better either). We can also remark, with a knowing wink, that this is actually a desirable result for the theory, since these non-causal cases are precisely those in which the concept of truth carries dubious credentials. Causal dependence is what truth basically consists in, so anything non-causal will struggle to qualify as true—except perhaps by extension or metaphorically or fictitiously. In the clearest cases truth amounts to causation by fact–we needn’t get too worked up about peripheral cases. Or we could simply stipulate that there are two kinds of truth requiring two kinds of theory: causal theory for one kind and correspondence theory for the other (or coherence or deflationary theory). It depends on the type of subject matter involved (and we already know there is a distinction between analytic truth and synthetic truth).   

As to deviant causal chains: there are none–so long as a fact causes a belief in that fact we will have truth. As to facts as causes: we should be liberal with the notion of cause, but if we decline so to be, we can always choose another kind of cause (say, event causation), and let that be the cause of belief. If you don’t think beliefs have any causes at all, I invite you to substitute whatever else you think is responsible for beliefs; and if you think nothing is responsible, you are beyond help. We can thus make the standard dialectical moves in response to the standard objections. At worst we concede that no causal analysis of the concept of truth is possible but suggest instead that we are offering a better picture of truth, one that sees truth as a passive effect of reality not as an active mapping onto reality (as with the correspondence theory). The world gives us truth by acting on us; we don’t achieve truth by contriving to depict it. This is a theory that works nicely for animal truth: animals have true beliefs because the world acts on them to install beliefs (or some more primitive representational state); they have no need to strive for truth. When facts cause beliefs they automatically produce truth, whether in mouse or man.

            Here is a more difficult counterexample: the case of random truth. Suppose I am making random statements about the color of things in some unknown part of the world, most of which are false, but by chance I hit on a true statement about the color of a flower there—I have said something true but the fact in question was not the cause of my saying it. The case must be admitted: there is such a thing as an accidentally true statement (similarly for a case of wishful thinking that just happens to produce a true belief). But surely the case is exceptional: the vast majority of cases are those in which the belief’s truth results from the fact in question—where we can know the belief is true just by knowing the person’s causal history. In the random truth case we can’t infer truth from knowledge of the person’s causal history. It’s a bit like introducing by stipulation a name for an unknown soldier and succeeding thereby in referring to a certain individual long dead: you do name a person without there existing any causal link to that person, but the case is quite unlike standard cases of naming. Truth is rooted in causation by facts though it can break free of these confines in unusual circumstances; we shouldn’t give up the basic insight in order to accommodate exceptional cases.  [4] Hard cases make bad law and all that. At a pinch we can retreat to a genealogical theory: this is how the concept of truth started out, but it might develop new forms alien to its origins. We must cling to the initial insight derived from perceptual beliefs: their truth consists in the fact that they are caused in a certain way, i.e. by the very fact they represent. The fact by itself will guarantee truth; we just need to add the relational conditions that enable beliefs to be true—that they exist and are externally caused. Once all this has been stated there is nothing further for talk of truth to add: the distinction between truth and falsity emerges from the distinction between fact-caused belief and fantasy-caused belief (to put it simply). What does an ascription of truth add to the assertion that a person’s belief that p was caused by the fact that p? It is quite redundant.

            The causal theory of truth, like other causal theories, can lay claim to the honorific label “naturalistic”: truth is primarily a property of empirical particulars (beliefs, statements) not abstract propositions, and it consists in a causal relation between agent and world. It is not conceived as a mysterious mapping or isomorphism or picturing; nor is it declared an irreducible primitive. It is a relation between the mind and the world that consists in a kind of causal connection, particularly via the senses. We observe that people’s beliefs are shaped by the world of fact and we call those beliefs true because of it; we also observe that sometimes people’s beliefs result from other factors (bias, illusion, wishful thinking) and these beliefs we call false (though they might in odd cases be true by chance). Truth

  [1] One version of the correspondence theory (there are many) equates truth with “designating an existing state of affairs”: the causal theory replaces the designation relation with a causal relation but retains the general form of the correspondence theory. We could view it as proposing a causal theory of the designation relation between beliefs (or statements) and states of affairs. It thus “naturalizes” such designation—as a causal theory of names “naturalizes” the naming relation. 

  [2] Note the analogy to causal theories of names: there is a social dimension to the causal relations involved, as well as experts and deference. Thus some beliefs are directly caused by facts while some are caused via chains of communication radiating out from an original encounter. Testimony exploits causality to transmit truth—as chains of communication can transmit reference.

  [3] An attractive feature of the causal theory is that it explains the referential transparency of truth: if “Hesperus is a planet” is true, so is “Phosphorous is a planet”. This is explained by the fact that causal statements are themselves transparent. The transparency feature is not captured by disquotational theories, since the disquoted statement is just the original statement. But causation is indifferent to mode of presentation or verbal formulation.

  [4] One thing we can say is that in standard cases true statements about color are caused by the facts. So the theory can be reformulated to assert that a given belief is true if and only if it is in standard cases caused by the facts