"If I were asked to summarize the philosophy of Objectivism in a single sentence, I would say that Objectivism holds:
a) that existence, reality, the external world, is what it is, independent of man's consciousness, independent of anyone's knowledge, judgment, beliefs, hopes, wishes or fears - that facts are facts, that A is A, that things are what they are;
b) that reason, the faculty that identifies and integrates the material provided by man's senses, is fully competent to know the facts of reality;
c) that man's perception of the facts of reality must constitute the basis of his value-judgments, that just as reason is his only guide to knowledge, so it is his only guide to action;
d) that man is an end in himself, not a means to the ends of others, he must live for his own sake with the achievement of his rational self-interest as the moral purpose of his life, neither sacrificing himself to others nor sacrificing others to himself;
e) that no one has the right to seek values from others by the initiation of physical force;
f) that the politico-economic expression of these principles is laissez-faire capitalism, a system based on the inviolate supremacy of individual rights, in which the exclusive function of government is the protection of rights;
g) that the absence of these principles from men's mind and actions is responsible for the present state of the world."
This statement was excerpted from Nathaniel Branden's opening lecture in his series, "Basic Principles of Objectivism" (available on this site for download).