I've been making my way through Bergson's Matter and Memory, and on the side have been reading some related articles from the Cosmos & History issue dedicated to the question, "What is Life?"
In addition to that I've latched back into some books concerning Hegel and the philosophy of biology, glancing back through relevant sections of Hegel's own book on the philosophy of nature.
In essence I have been posing Hegel's necessitarianism against Bergson's emphasis on creativity, decision, and free will (found also in Bergson's Creative Evolution and Time and Free Will) as I wrangle with the question, "what is life?" Perhaps I would say that my broader interest in that question concerns the relationship between life and matter.
Bergson's Matter and Memory is a tough book, but well worth the labor.