Like most astrologers I’m asked, sometimes indirectly, how or why I would “believe” in astrology. “You’re so rational -- why?” It’s a valid question based on our time and place in history.
There is already a quantity of excellent literature available which deals with factual evidence on the matter. Each individual needs to make their own judgement on the validity of evidence, but one cannot form an opinion on something until they have some experience at their disposal (rather than popular conceptions and misconceptions). We should have learned long ago that these conceptions/misconceptions were fallible. The whole “earth supported by a giant tortoise thing” had the full approval of scientists of the day. At the end of the day, the proof is in the pudding. That can only be determined once an individual has direct experience with the knowledge, and data, and not something that can be crystallized second-hand. Best bet is to ask for a list of sources and start the process.
With that in mind, I have a couple links to jump-start your process of uncovering workable frame-works for astrology. Spoiler alert -- there’s no complete answer.
My Favourite podcast is http://theastrologypodcast.com/
Dr. Saffron Rossi and Dr. Keiron Le Grice have recently published Jung on Astrology that serves as, perhaps, the first primary source for condensing Jung’s views (and why he practiced and used astrology with a lot of his clients).
Audio podcast interviews on Archetypes and the Mechanics of astrology:
Cosmos and Psyche: Intimations of a New World View, by Dr. Richard Tarnas is a must-read, too.
Also, few, if any, astrologers believe that the planets actually 'cause' anything to happen here on Earth. Most are inclined to believe that some kind of mirroring effect takes place and that everything in the Universe is interdependent.
Good luck! Astrology has been used across almost all cultures, for time immemorial. Get a reading done with a professional astrologer. Ask questions -- inquire. Contact me and I’d be happy to discuss why a rational guy has invested his time and energy into this powerful study.