(October 10, 2018 at 4:27 pm)SteveII Wrote:(October 10, 2018 at 4:03 pm)polymath257 Wrote: The fact that there is no internal contradiction means it isn't logically eliminated. So, yes, we get to assume any axiom that isn't contradictory. The *logic* isn't violated.
Metaphysics is bunk. Pure and simple. There is no such thing as valid metaphysical reasoning: only metaphysical assumptions, usually invalid ones.
I won't come up with a metaphysics article because I consider *all* metaphysics articles to be bunk. But, the math and physics articles are very clear about the *logical* possibility of an actual infinite.
The problem I have with 'concrete' objects is that I don't consider the word 'concrete' to be well defined. For example, is an electron a 'concrete object'? Give reasons for your answer. is a neutrino a 'concrete object'? is a photon? These are the *actual* objects from which the universe is built. These are the ones that matter. Whatever your vague notion of 'concreteness' is irrelevant to the actual physics. And if your metaphysics doens't allow the actual physics, then it is simply invalid.
Good. Further conversation on this is impossible because this conversation is about metaphysical concepts and you just declared all metaphysics to be "bunk". I'll leave you with a list of the "Central Questions" of metaphysics--but you probably don't care about any of them, they're just "bunk"...
2.1 Ontology (Being)
2.2 Identity and change
2.3 Space and time
2.4 Causality
2.5 Necessity and possibility
https://en.wikipedia.org/wiki/Metaphysic..._questions
It also sucks for science, since these and other metaphysical concepts are required to have a philosophy of science--without which science cannot exist. Damn, what a shame when they all find out...
Let me put it this way. Synthetic a priori knowledge is impossible. Mathematics consists of rearranging assumptions using an assumed logic. In other words, axioms and rules of deduction. Science works by taking observations, formulating testable hypotheses based on those and making predictions based on those hypotheses and seeing if they are verified through further observation.
Metaphysics, on the other hand, tends to assume certain categories make sense, assumes that certain things are necessary a priori, and that even the concept of 'identity, causality, space, time, necessity, etc' even have meanings outside of pure formal systems or observations testing. The basis of science, which you seem to ignore is NOT some metaphysical axiom system, but simply that we should test all of our ideas about the 'real world' by testing. That means even ideas about space, time, and causality. Pure philosophy can get nowhere because the range of actual logical possibilities is too great and pure logic too weak to eliminate most of them. Only actual observation and testing is strong enough to eliminate the falsehoods.
In terms of overall philosophy, I am closest to Hume. Kant made some mistakes in thinking space and time are synthetic a priori (they are not). The list of topics you gave can be largely addressed via the scientific method. To the extent they cannot be so, they are literally meaningless.