Truth as Consistency

Truth as Consistency

I will present a new theory of truth. It can be stated thus: for a proposition to be true is for it to be consistent with reality.[1] For “snow is white” to be true is for it to be consistent with the fact that snow is white; “snow is black” is not consistent with snow being white, so it is false. It can’t be that “snow is black” is true and yet snow is white; but “snow is white” being true is eminently consistent with snow being white. The part of reality referred to by “snow is white” is the state of affairs of snow actually being white, but “snow is black” refers to no actual state of affairs. The latter sentence is not consistent with reality, but the former is. If someone asserted that snow is black, we could reply that that statement is not consistent with reality, thereby stating that the proposition in question is not true. It will be noticed that this relation of consistency holds between propositions and parts of reality; so, it isn’t the same as consistency between propositions. Some may find this objectionable, but it really isn’t. It is a perfectly natural way to talk. States of affairs can be consistent or inconsistent with each other, as well as propositions; we are simply extending the concept to a relation between propositions and facts (constituents of reality). There is consistency between propositions, consistency between states of affairs, and consistency between propositions and states of affairs. There is nothing incoherent about any of this; logic straddles these domains.  The theory is thus intuitively appealing and logically kosher.

What is nice about this theory is that it dispenses with the old notion of correspondence, which was never terribly clear. Doesn’t “snow is black” correspond with the fact that snow is white in the sense that it maps onto that fact via the falsehood relation? To rule this out we have to say, “truth-making correspondence”, but that is circular. The word “correspondence” merely gestures at a relation we haven’t yet articulated; it trades on reading truth into it. It doesn’t provide a concept that has an independent use—a prior meaning. But the word “consistency” does just that; it uses a concept we are familiar with from logic, not some ill-defined newfangled word. We know what consistency is already; we just have to extend its use to a new domain, viz. proposition-reality consistency. Thus, we can say that the sentence “’snow is white’ is true and snow is not white” expresses a logical contradiction, since the first conjunct entails that snow is white—it entails that reality is a certain way. Truth is simply consistency with the fact a sentence states: the proposition that snow is white is consistent with the fact that snow is white.

It might be said that the proposition that snow is white is consistent with many facts (infinitely many), but doesn’t it have just one truth-maker, viz. the fact that snow is white? Don’t we need to be more specific? All right, we can do that: we avail ourselves of the concept of entailment. Proposition and fact are not just consistent; the former entails the latter. That seems right: you can deduce, from “’snow is white’ is true”, that snow is white—but not that grass is green. We therefore obtain the entailment theory of truth: for a proposition to be true is for it to entail a (specific) fact—the fact it states. And the entailment cuts both ways: if it is a fact that snow is white, then it must be the case that “snow is white” is true. Then we have a conjunctive theory: for a proposition to be true is for it to be consistent with reality and such as to entail a specific fact of (or in) reality. The proposition that snow is white is consistent with reality and it entails the specific fact that snow is white. But the initial formulation was fine as it stands: to be true is to be consistent with the facts or with reality (compare “to be true is to correspond to the facts or to reality”). Truth, we feel, is a relation, and so it is under the consistency theory—not a correspondence relation, whatever exactly that is. Truth is a logical relation, familiar to us from logic. Thus, truth is a logical concept; indeed, the most basic of logical concepts. It needs no further enrichment. It may not be redundant, but it is extremely slender (rail-thin).[2]

[1] The idea for this paper came, improbably enough, from an Iranian comment on President Donald Trump: “His statement is not consistent with reality”. Is this a diplomatic way of saying that Trump’s statement was a lie, or at least false? Maybe in Iran the theory I am proposing is a commonplace.

[2] This is a minimalist theory of truth in that it invokes no heavy machinery in its analysis of the concept of truth; it relies solely upon the logical notion of consistency. But it is relational and is not just a redundancy theory. We do need a concept not contained in the proposition itself to capture the concept of truth, viz. consistency. By my count, this is the fifth theory of truth I have invented (see this blog), more than all the usual theories combined; it seems just a bit too easy to define truth. My theories are not incompatible but can be combined to form a composite picture of the nature of truth. Concepts don’t have just one analysis; they are more complex than that.