The Objectivist view of existence culminates in the principle that no alternative to a fact of reality is possible or imaginable. All such facts are necessary. In Ayn Rand’s words, the metaphysically given is absolute.
By the “metaphysically given,” Ayn Rand means any fact inherent in existence apart from human action (whether mental or physical)—as against “man-made facts,” i.e., objects, institutions, practices, or rules of conduct that are of human origin. The solar system, for example, is metaphysically given; communication satellites are man-made. The law of gravity is metaphysically given; the laws against murder are man-made. The fact that man’s life requires food is metaphysically given; the fact that some men, such as ascetics or anorectics, prefer to starve is man-made.
Let us focus now on the metaphysically given. As soon as one says about any such fact: “It is”—just that much—the whole Objectivist metaphysics is implicit. If …
Read the rest in Objectivism: The Philosophy of Ayn Rand.