25. Forms of truth

Notions of truth correspond with ideas of knowledge. For the philosophical rationalist, such as Descartes, knowledge comes from innate ideas that are true because God infuses them. For the empiricist, such as Locke, something is true if it corresponds with reality, on the basis of objective sense data. For others such not already interpreted atoms of truth do not exist, and truth is coherence with a relevant body of knowledge. That can take the form of logical deduction from assumed premises, but also consistency or mutual reinforcement with things that are taken for true. That comes close to the notion of plausibility. There were ample conditions where it might have been refuted but was not. According to a related notion propagated by pragmatic philosophers, something is true if it is fruitful, i.e. contributes to successful practice, if it remains standing in action. 

There is a well-known distinction between analytic truth by definition or logical deduction, and synthetic truths of fact. The strict distinction has been criticized because truths of fact are often dependent on definitions and hence analytic truth. They are also theoretically laden, i.e. are theory-based interpretations of phenomena.

An entirely different notion of truth concerns ‘truth to form’ as in ‘that is not a true work of art’. It can also refer to lack of authenticity, with falsehood referring to insincerity, false pretence, and the like, as in ‘you don’t truly mean that’. One might speak of moral truth, as true to moral precepts, as in ‘he is truly a good man’.

Traditionally, a clear distinction was made between the ‘is’, the descriptive and the ‘ought’, the normative. That also has become doubtful. Observations, and their theoretical interpretations, are routinely subjected to standards of methodology, which are normative. Descriptive statements are mostly intentional, i.e. are part of a project, directed towards a goal, an interest, as a result of which one looks in selected directions and ignores others. In other words, scientific theory is value laden, by both methodological norms and intentions. Many economists, for example, pay no attention to theories that are not mathematically formalized according to the prevailing fashion.   

Much in our use of language is a form of action and a matter of effectiveness rather than a matter of truth or falsity. In his work on Doing things with words, Austin made a distinction between expressions that are locutionay statements, with propositional content, saying something about the world, and illocutionary expressions that are intended to affect someone, such as an order, request, accusation, and the like. Many statements are both at the same time. Earlier I used the example of my wife calling out ‘that is not a screwdriver’ as I use a knife to turn a screw. That has propositional content but the point of it is illocutionary.