Abstract
One of the most notable theses of McTaggart’s system is his doctrine of logical determinism, the contention that—on grounds of fundamental logical principle—everything in the world must of necessity be just exactly as it is, that nothing could possibly differ in any particular from its actual condition. McTaggart holds that given that any substance in the world is what it in fact is, every substance must be just as is. And so “all that exists, both substances and [their] characteristics, are held together in one system of extrinsic determination”. For “every fact about every other substance [different from the universe itself] extrinsically determines every fact about the universe, and…every fact about the universe extrinsically determines every fact about every other substance”. And, therefore, “the supposition that anything should be different from what it is, therefore, is one we have no right to make”. Things are bound up in one vast network of mutual necessitation.