Spirituality – Metaphysics

Central Questions

Necessity and Possibility

Metaphysicians investigate questions about the ways the world could have been. David Lewis, in “On the Plurality of Worlds,” endorsed a view called Concrete Modal realism, according to which facts about how things could have been are made true by other concrete worlds, just as in ours, in which things are different. Other philosophers, such as Gottfried Leibniz, have dealt with the idea of possible worlds as well. The idea of necessity is that any necessary fact is true across all possible worlds. A possible fact is true in some possible world, even if not in the actual world. For example, it is possible that cats could have had two tails, or that any particular apple could have not existed. By contrast, certain propositions seem necessarily true, such as analytic propositions, e.g., “All bachelors are unmarried.” The particular example of analytic truth being necessary is not universally held among philosophers. A less controversial view might be that self-identity is necessary, as it seems fundamentally incoherent to claim that for any x, it is not identical to itself; this is known as the law of identity, a putative “first principle”. Aristotle describes the principle of non-contradiction, “It is impossible that the same quality should both belong and not belong to the same thing … This is the most certain of all principles … Wherefore they who demonstrate refer to this as an ultimate opinion. For it is by nature the source of all the other axioms.”

Luc Paquin