and always = A and only a TSZ “nihilist” .would deny it, says Barry Arrington.
A=A is infallibly, necessarily true
What does this claim even mean? That something denoted by A is identical to something else also denoted by A? Clearly not.
That if we devise a system of logic in which we declare that A always equals A , A must always equal A? Well, duh.
That the only possible logic system is one in which A is always equal to A? Well, no – fuzzy logic is a very useful logic system, and A is sometimes only approximately equal to A, or may equal A if it passes some threshold of probability of being A.
So what does he even mean? Is his claim even coherent?