In ordinary language, the metaphysical status of ‘truth’ is very much messed around with. “John tells the truth” does not mean that John is canvassing something that exists independently of John himself. The quote may also be written as “John tells a truth”, or even better: “What John says, is true.” This refers to here and now. In the expression, “What John says” is the sentence’s subject, “true” is its predicate, just like in “The table is brown.” However, “What John says” refers to something.
Now let us assume that John said: “The table is brown.” If from this we distillate a non-John-dependent statement about reality, we might go for “It is true that the table is brown.” Obviously, in this sentence “it is true, that” adds nothing, since the table is either brown or not-brown, end of story.
Predicates express properties. On the classic notion, also known as Leibniz’ Law, an individual object has essential properties that make it differ from all other existing objects. In mainstream metaphysics, existence itself is not considered a property. It would be very strange to say: “This article possesses the qualities ‘clear’, ‘short’ and ‘interesting’, and it is ‘existing’.
According to some philosophers, particulars exist because we have sensory impressions of them. Others hold that everything that can be conceived exists, even if it lacks time-and-place related properties, like a centaur or a dragon. Between these two there are two more categories: facts and occurrences. To these, the property ‘exists’ adds nothing either. “It is true that the table is brown” or “It is a fact that the table is brown” is only a superfluous confirmation of “The table is brown”.
Speaking of truth and existence, circular reasoning is luring. Discussing sentences like “It is true that Santa Claus does not exist” might keep this article going for quite some time, but if we change the statement to “It is true that truth does not exist”, it becomes obvious that this approach won’t take us very far…
Our metaphysical starting point has to be that everything existing either has properties or is itself a property. We need to take a position on properties, defining what they are, to then either get to know the set of properties that bring about truth – if there is such a set –, or to characterize truth as a property.
Let us assume that truth exists. According to a very classical division, truth might then be either a particular (a spatiotemporally unique existent) or a universal (an existent possibly present at various places at the same time).
If truth is a particular individual, to define truth would then mean to define its unique set of properties. This is not very promising since the only thinkable property of truth would be that truth is true; truth cannot be ‘red’, ‘odorless’ or ‘spongy’. We might say, however, that truth is ‘hard’, ‘surprising’ or ‘significant’. In the latter case, we are probably thinking of a particular truth in a particular case, saying a lot about a truth, but nothing about the character of truth as such.
People may attribute universal properties to truth, like “truth is always hard”. Whatever ‘hard’ means – ‘hard to bear’, ‘inevitable’, … –, they use it as an essential property of truth as individual existent. So, apart from being ‘true’, what might be the essential properties of truth enabling us to distinguish truth from any other existing thing? I wouldn’t know.
Quite some philosophers have said that not objects, but properties are the elementary entities of reality. A property like ‘brown’ means that there exist unique brownnesses, that somehow resemble each other. Its brownness constitutes my table, together with lots of other properties like ‘of wood’, ‘oval’, ‘in my living room’ etc. etc. But if we apply this idea to truth, it would mean that all truths are individual existents, or, simply put, that everything that is true has its own particular truth.
This brings on two problems. The first is that this kind of truth lacks a common denominator. If we try to define ‘true’ as a class containing all individual truths, we should also be able to tell why a particular ‘truth’ classifies as true – or why not. The other problem is that the basic purpose of the ‘truth’-property is gone, which is to somehow distinguish between true and false. Truth just doesn’t come in degrees. Therefore, if seen as particular property, truth is trivial.
We might also start from truth as a universal, in which case ‘true’ might be a property of any existing particular, fact or event, and simultaneously appear in different places. Note that universalism claims that universals are entities existing in reality. This so-called realistic universalism famously came in two classical types.
Plato thought that everything existing was the imperfect copy of perfect and universal Forms. Plato’s Forms were transcendent, existing in a reality outside the physical world. The perceivable world only imperfectly mirrored the Forms, all horses, for example, being only worse copies of the perfect form Horse, all brown horses also showing worse shades of the perfect form Brown. In this view, all truths are imperfect copies of the ideal Truth; examples of various truths are unfit to define Truth as Form, since this would turn the metaphysical hierarchy upside down. The same is the case with comparable concepts like justice, beauty, virtue, etc.
For astute philosophers, there is the possibility of ‘understanding’ of these Forms. Later Platonists saw the Forms as expressions of ‘the One’. Early Christian philosophers integrated the One into Christianity, where it became the philosophical nature of God as the source of everything existing, this of course including truth. When Jesus said “I am the way and the truth and the life. No one comes to the Father except through me” – John 14:6 –, this was probably supposed to be read as Jesus offering a pathway to understand God. But once the Holy Trinity rose above discussion, the second part of the quotation lost its original meaning; the whole could just as well be simplified to Jesus, God and truth being modes of one single superior being. This is the root of the belief of many that truth exists on its own account and that it can be ‘understood’.
However, Plato’s student Aristotle held that universals were immanent in the perceivable world. Universal properties show themselves in individual existents. This enables truth to pop up in just about any object or concept, and in a way uncompromised by Plato’s imperfect mirroring. Sounds promising, if it weren’t for another of Aristotle’s findings, the law of the excluded middle. According to this law, statements about particular things, facts or events are either true or false, there is no middle way. As I wrote above, this makes ‘true’ a metaphysically trivial property for objects as well as for facts and occurrences.
We have only two proper ways to think of truth. Either truth is equal to ‘being’, that is: reality itself, or truth is the expression of the predicate ‘true’. Martin Heidegger writes that ‘truth’ is a mistranslation of the greek αληθεια,, (aletheia) which in fact means ‘disclosure’. Therefore, truth adds nothing to being as such. The other possibility is to use the ‘true’ predicate to state the existence of proof. Such proof requires propositional connections between objects, facts or occurrences. So ‘true’ is more than a predicate for a single something: it expresses a belief in the existence of a relation.
The same goes for synonymic expressions like ‘is real’, ‘is the case’, ‘is absolutely certain’ and ‘is beyond the shadow of doubt’, all serving to express the certainty of facts relating and nothing more. Note that these predicates leave more than enough room for degrees of truth, ranging from ‘largely true’ or ‘probably true’ down to ‘almost certainly bullshit’.