In Defense of Truthmaker Maximalism

I tackled this topic several years ago, but I think it’s time to revisit it again. I’m going to argue that truthmaker maximalism (TM)—the view that every truth is grounded in some reality that makes it true—should not be regarded as a particularly controversial thesis. It’s virtually a corollary of the correspondence theory of truth (CTT). But “virtually” I mean that, while it’s not strictly speaking a corollary of CTT, it makes explicit something that usually presupposed by those who hold to CTT. The two principles, TM and CTT, fit very nicely together.

I will begin (§1) with CTT and show how it implies a distinction between truthbearers and truthmakers. I will then (§2) turn to TM and show that it adds an important and commonsensical qualification to the truthbearer/truthmaker distinction. I will next (§3) compare and contrast the correspondence and truthmaking relations and show how they complement each other. Finally, (§4) I will briefly rebut several common objections to TM.

§1. The correspondence theory of truth

The classical statement of CTT comes from Aristotle (Metaphysics 1011b25): “To say of what is that it is not, or of what is not that it is, is false, while to say of what is that it is, and of what is not that it is not, is true.” As Marian David notes in his SEP entry on CTT, this is a rather minimal version of CTT. It does make clear, however, that truth consists in a concurrence or agreement of some sort between reality—”what is”—and what can be “said” about reality, that is, something that describes or represents reality as being a certain way. As David notes, there are many different versions and formulations of CTT that have somewhat different takes on what “correspondence” amounts to and on how the terms of the relation—truths, on the one hand, and their correlates in reality, on the other hand—are best understood. But the basic idea is of CTT is that truth is a relation of correspondence between reality and a representation of reality, whether the latter be a proposition, statement, thought, or what have you. When a representation adequately corresponds to reality, we say that it is true or bears the property being true. So we can call the representational term in this relation a truthbearer. It is something of which truth can be predicated. Likewise, we can call the reality term in this relation a truthmaker. It is that in reality which makes a truthbearer true by corresponding to it.

CTT says, then, that truth is a relation of correspondence between a truthbearer and a truthmaker. Talk of “truthbearers” and “truthmakers” allows us to theorize about truth while staying as neutral as possible with respect to what sorts of things truthbearers and truthmakers are. A truthbearer is whatever it is (whether beliefs, thoughts, ideas, judgments, statements, assertions, utterances, sentences, propositions, etc.) that can occupy the representational term in the correspondence relation. A truthmaker is whatever it is (whether facts, states of affairs, events, things, tropes, properties, worlds, etc.) that can occupy the reality term in the correspondence relation. As for correspondence, it can be understood as a broadly semantic relation between the representational content of a truthbearer and the intelligible content of some relevant portion of reality (a truthmaker). If the intelligible content of some existing truthmaker contains the representational content of the truthbearer, then the latter is true. Otherwise, the truthbearer is false or at least not-true.

For example, the statement “the cat is on the mat” and the proposition <the cat is on the mat> describe a way reality conceivably could be, namely, that it could include a designated cat’s being on a designated mat. That’s their meaning or representational content. To understand the statement or proposition is to grasp that content. Likewise, if reality is that way, that is, if the designated cat and the designated mat both exist and the former is spatially positioned “on” the latter, then reality has a certain structure, an intelligible content, that could accurately be described by <the cat is on the mat>. Reality includes much other content besides, but the point is that there’s an agreement between the representational content of the truthbearer and the intelligible content of some relevant portion of reality, which reality thereby provides a truthmaker for that truthbearer.

§2. Truthmaker maximalism

It is an obvious corollary of CTT that for every truth there is a truthmaker, a portion of reality the existence of which renders or makes that truth true. That brings us close, but not all the way, to TM. As philosopher D.M. Armstrong puts it,

Anybody who is attracted to the correspondence theory of truth should be drawn to the truth-maker [sic]. Correspondence demands a correspondent, and a correspondent for a truth is a truth-maker. (A World of States of Affairs, p. 14)

What truthmaker maximalism (TM) adds to CTT is the idea that reality is the grounding term in the correspondence relation. In other words, TM says that in addition to the semantic relation of correspondence between a truthbearer and a truthmaker, there is also an explanatory relation of grounding: reality grounds truth. Reality is explanatorily (and ontologically) prior to truth. What’s true is true because reality is the way it is, not vice-versa. Put more formally, TM says that for every truth T there exists a ground G such that G → T. The right arrow (→) here is not logical but ontological. It says that G’s existence is ontologically sufficient for T’s truth and that the order of ontological explanation or grounding runs from truthmaker to truthbearer.

So understood, TM is commonsensical. That reality is ontologically prior to truth can be easily confirmed. For example, I am holding a pen in my hand, so the proposition <I am holding a pen> is true and <my hand is empty> is false. As soon as I drop the pen, however, <I am holding a pen> becomes false and <my hand is empty> becomes true. Truth changes because reality changes. We know the explanatory order runs in that direction because we can directly manipulate reality, whereas we can’t manipulate truth except by way of manipulating reality.

The importance of TM for philosophy is this: It mandates that one’s ontology needs to be robust enough to underwrite whatever truths one deigns to posit. Truths can’t “float free” without ontological moorings. That’s something I think every philosopher should agree on.

§3. CTT versus TM

It is important to note that while CTT and TM are mutually complementary and are close cousins, so to speak—they both affirm that truth depends on a relation of some sort between a truthbearer and a truthmaker—they are different relations.

Correspondence is a broadly semantic and symmetric relation. The relation goes both ways. If the content of the truthbearer corresponds to the content of the truthmaker, then the converse is also true: the content of the truthmaker corresponds to the content of the truthbearer.

Truthmaking, in contrast, is an anti-symmetric explanatory relation. The relation goes one-way, except in certain special cases (see note).

Because of their differences, correspondence and truthmaking answer different questions:

• Truthmaking answers an explanatory question: Why is this truthbearer true? Answer: It is true because there exists a corresponding truthmaker.
• Correspondence answers an adequacy question: Why is this truthmaker adequate to make this truthbearer true? Answer: The intelligible content of the truthmaker contains the representational content of the truthbearer.

§4. Some objections to TM rebutted

• Objection 1: TM is self-refuting because there is no truthmaker for TM.
  Reply: TM is a conceptually necessary truth. Like all other such truths, it is its own truthmaker.
• Objection 2: TM generates a self-referential paradox: Let M = “This statement has no truthmaker”. If M has a truthmaker per TM then it both does and doesn’t have a truthmaker.
  Reply: I respond the same way I respond to the Liar paradox (“This sentence is false”). The self-referential sentences in question lack determinate meaning and so aren’t proper truthbearers. (Liar-style paradoxes are a problem for every theory of truth. So if there needs to be an exception to TM, this is probably the least ad hoc place for it.)
• Objection 3: If nothing existed, then it would be true that nothing existed, but there wouldn’t be any truthmakers.
  Reply: (1) If nothing existed, then there wouldn’t be any truthbearers either, so nothing would be true. The objection makes an illicit use of idea that if P then True(P), a corollary of the disquotation principle. Like that principle, it can’t be used for ontological bootstrapping (see MPQ #5 in this post). (2) Arguably, it is metaphysically impossible that nothing exists.
• Objection 4: Negative existential truths (e.g., there are no unicorns) lack truthmakers.
  Reply: The totality of reality is a truthmaker for this. So is God’s having a unicorn-free experience of reality.
• Objection 5: General truths (e.g., all cows eat grass) lacks truthmakers.
  Reply: If the generalization is a contingent truth, then the collection of all individuals in the population provides a truthmaker. If the generalization is a necessary truth, then the natures or essences of the things in question is the truthmaker.
• Objection 6: Truths about the past and the contingent future lack truthmakers.
  Reply: (1) Regarding the past, just build it into the ontology. Either be an eternalist or growing-block theorist, or for a presentist ontology admit presently existing and necessarily persistent traces of all past events (e.g., God’s memories). (2) Regarding the future, one can be an eternalist, posit brute contingent “facts” about the future, or simply deny that there are any settled truths about future contingents.
• Objection 7: Counterfactual truths lack truthmakers.
  Reply: For normal counterfactual truths (e.g., if I were to place this ice next to that fire, it would melt), one can admit causal powers into one’s ontology and root those in the natures of the things involved. For Molinist middle-knowledge counterfactuals, I think one can do no better than appeal to brute contingent “facts”, however unsatisfying those may be from an explanatory perspective.
• Objection 8: TM is badly motivated—it’s an ideologically loaded principle whose “whole point” is to “catch cheaters” (Sider, Four-Dimensionalism, pp. 40–41).
  Reply: Wrong. The point of TM is merely that truth is grounded in reality. That claim is as close to being subject-matter neutral as CTT is. Since truthmaking is an explanatory relation, however, canons of explanatory adequacy (simplicity, sufficiency, informativeness, coherence, etc.) can be invoked to assess whether some truthmaking proposal is a good explanation or not. But—this is important—canons of explanatory adequacy are independent of TM. They are auxiliary ideas that should not be conflated with TM itself. Paul Horwich puts this point well:
  The demand for truth-makers doesn’t help “catch cheaters” at all. Just acknowledge, e.g., some brute counterfactual facts about sense data, or brute dispositions to behave in one way or another, or brute facts about what happened in the past or will happen in the future. What’s unsatisfactory about these posits isn’t that if they existed they’d fail to make true statements about unobserved objects or statements about mental states that failed to manifest themselves in actual behaviour or statements about the past or future. The problem is that we have difficulty in understanding how such facts or dispositions could be explanatorily sound. [emphasis added]