‘What is truth?’ Pontius Pilate (John 18:38)
It’s an old question. But one that has taken on new importance in an age increasingly labelled ‘post-truth’. One core part of the question is what determines truth. Some claim that truth is a subjective notion, perhaps determined by an individual's perspective. Others think truth is objective, determined by the configuration of the world. Each approach raises more questions. How does an individual's perspective/the world determine what is true? Are there really two notions here that have become confused, or is only one plausible? It also seems difficult to see how either approach explains mathematical truths such as 2+2=4.
My PhD thesis studies the concept of truth. In particular, the way the notion was understood by German mathematician-cum-philosopher Gottlob Frege. Frege holds a unique perspective on truth. He claims that truth is indefinable. And yet he also holds that it is a substantial notion that grounds all factual claims. This gives him a unique perspective on the role of logic. While science studies truths, logic studies truth itself. For logic describes the laws of truth. The laws by which we reason. So logic, for Frege, is the fundamental science.
This suggests a middle road. Perhaps truth resides (first and foremost) in the inter-subjective experience of correct thinking. In the law-like principles of valid reasoning. 2+2=4 is true, not because the world is arranged a certain way, nor because we have collectively or individually decided to treat this claim as true, but because we cannot reason that it is false. It is true because it is an absolute inter-subjective fact. Truth is a notion grounded in the interaction between thinking subject(s) and thought about object(s).
(While in New Zealand, I studied a BA with a double major in Philosophy and Mathematics, as well as an MA Philosophy. Since arriving in Cambridge I have completed an MPhil in Philosophy (also as a Gates scholar) and am now engaged in a PhD.)