Some of Spinoza's ideas are part and parcel of our culture, but to the best of my knowledge Spinoza is absent as a reference from the modern efforts to understand the biology of the mind. This absence is interesting in itself. Spinoza is a thinker far more famous than known. Sometimes Spinoza appears to rise out of nothing, in solitary and unexplained splendor, although the impression is false-in spite of his originality he is very much a part of his intellectual times. And he appears to dissolve as abruptly, without succession-another false impression given that the essence of some of his forbidden proposals can be found behind the Enlightenment and well beyond in the century that followed his death.