There are only a couple whom I study and endorse: Aristotle and Ayn Rand are the only people who acknowledge reason as the only tool to discover knowledge.

I am a new Intellectual, so far Ive gathered:
Kant was anti reason and held mysticsm as an absolute.
Nietzche, although not an altruist, thought other should be sacrificed to oneself.
Plato - complete mystic and believed any form of knowledge and success was not earned but given by God.

Ayn Rand philosophy, although completely thought of on her own, was influenced by Aristotle. Reason being the only absolute. "The philosophy for living on Earth"