Every grain of sand is a link in an essential causal chain.
St. Thomas laid the intellectual groundwork for modern natural science — the absolute distinction between existence and essence.
I can describe anything you like in whatever detail you like, but you can’t know whether it exists or not merely by its description.
Nature is like a stack of books, sessile, until moved.
In my ongoing debate with biologist Jerry Coyne, frequent reference is made to Aquinas’ Five Ways, particularly to his Prime Mover argument.