Aries is not a sign associated with philosophy — that is Sagittarian territory according to tradition. However, the Ram knows how to get to the essence of things. In fact, the father of modern western philosophy himself, René Descartes is an Aries Sun. His Sun conjuncts Uranus, the planet of rebellion and innovation, and indeed he upturned 2000 years of received wisdom when he sat down one evening by the fire and started to cogitate about what he really knew for sure, and what he just thought he knew.
Descartes famously realised that the only thing he could really be sure of was this: “I think therefore I am.”
His very methodical approach to ideas may have something to do with his Moon in Taurus.
The 20th century philosopher Erich Fromm, an Aries Sun too, also brings us back to basics. He has the “philosopher’s Moon” in Sagittarius and so, as you would expect, applied his ideas to many fields — politics, history, personal development. His book To Have or To Be? asks us a basic question: what is more important as humans, to own stuff or to be ourselves… Maybe a very pertinent question in our current times.
Here is an interview with him (by I believe Robert Robinson) discussing the ideas in that book.