Maimonides on the Origin of the World Book

It would be extremely difficult (and subject to endless debate) to pick the second most important book ever published. However, choosing the first one is easy: Spinoza's Ethics.

It is no wonder that, when asked if he believed in God, Einstein answered "I believe in Spinoza's God, who reveals Himself in the lawful harmony of the world, not in a God who concerns Himself with the fate and the doings of mankind". Similarly, Goethe, often referred to Spinoza as one of the few thinkers capable of "calming the fires on his young poet's soul"

The problem is that Ethics is also perhaps one of the most difficult works to comprehend out there. It is easy to admire Ethics but enjoyment only comes after thorough study. Spinoza's geometric approach and his choice to write in Latin don't exactly help, which is why J.Thomas Cook reader's guide is such a wonderful tool, providing not only explanation and discussion of the text but also historical context

When tackling the question of ethics, philosophers are trying to develop a system of rules by which to live an optimal life. Most rationalist philosophers take a reductionist approach beginning with basic axiomatic rules about the individuality of being (Descartes) or the nature of man (Hobbes). For Spinoza, who greatly admired both, they are just thinking too small: He begins with God, the only true substance, and a God that has nothing to do with the anthropomorphic gods of scripture but rather one which he equates with the totality of everything that will ever exists for all eternity. Spinoza is perhaps the first modern Pantheist and, if anything, he is closer to Philip K. Dick than to Saint Thomas Aquinas.

He comes to pretty powerful conclusions: If God is in all that exists and is all that exists, the only kind of true knowledge is the knowledge of God, that true knowledge, necessarily results in the dissolution of the illusion of free will and in the joyful acceptance of our place in the eternal substance. Hence, the most joyful life is a life devoted to the pursue of true knowledge.

To me, what is most interesting, is that the more we learn about neuroscience or physics and the closer we come to understanding mind as an emergent property of any substrate-independent brain , the non-local nature of reality, the true consequences of a quantum-entangled multiverse or nature's apparent propensity to homeostasis and autocatalysis...the closer we come to Spinoza. Even when reading cutting edge AI theorist like Karl Friston's free energy principle for systems within Markov blankets, I hear echoes of Spinoza's Conatus and the tendency of living things to maintain their "ratio"...Spinoza wrote his Ethics over a decade locked up in a basement in the 1600's...I can only imagine what he would write today...but after all, mind is eternal so you never know :)