There’s a basic distinction in philosophy between empiricism (from experience) and rationalism (from reason). This is something that was taught in introduction to philosophy when I studied it at University. Like many such broad distinctions there are many nuances and subtleties but the basic idea still holds.
Rationalist philosophers hold that the truth can be disclosed by reason alone. Plato and Platonism were broadly rationalistic. So too Descartes, Liebniz, and Spinoza.
Empiricist philosophers insist that true knowledge relies on sensible (sensory) experience. Very influential in the early modern English philosophers e.g. David Hume, John Locke, Bishop Berkeley.
Kant maintained that both the rationalists and empiricists were mistaken in claiming that their philosophies were sufficient for the attaining of truth. But empiricism is still highly influential in modern philosophy because of its foundational role in science, where it equates to validation by observational or experimental data.
Nominalism entered the picture in late medieval philosophy as a counter to the rationalism of Scholastic philosophers. The latter held to the reality of universals (=Scholastic realism) while nominalism (initiated by William of Ockham) believed that universals were only names (hence the designation.) Nominalism was an important forerunner of empiricism and is still the dominant influence in much of modern philosophy.
…is concerned not with the truth of propositions but with whether they are known. We can infer creatures suffering complete sensory deprivation, and yet 1+1=2 still being true; they are mutually exclusive. What is difficult is deciding whether such creatures could know that 1+1=2.
This is confused reasoning which presumes that there would be truths and propositions even if there were no minds. It fails to understand what a proposition or a truth is. It is a common confusion on TPF.
So if we say that logic requires terms which are manipulated by the mind, then we would want to ask about the way in which those terms are known. If the terms that logic manipulates can come only from the senses, then it is true that there can be no logical truths apart from the senses. If, on the other hand, there is what is referred to as “a priori knowledge,” then there are terms which are not derived from the senses, and there could also be truths apart from the senses. This is an old debate in philosophy.
Then as others have often pointed out before, you are a bona fide Platonist who does not realize that he is a Platonist, because he hasn’t thought through any of this. You think there are propositions and truths floating around independent of any minds.
I don’t usually read your posts, Leon, because of your habit of abusing the messenger rather than addressing the message. I see it continues.
A simple argument that undermines your account. Can you address it? This is about whether truth is a relation between a proposition and a mind or language; or the interaction between a proposition and the world captured by a T-sentence. The latter is not platonism.
There would not be. Possible world semantics provides the rough answer by giving us a semantics that keeps such things in order. Conceiving of a possibility does not make it so.
The idea that you can say how things are as if there were no mind to do the saying is a neat little absurdity. Folk working themselves into a spin trying to talk about what can’t be said.