Abstract
In 1835 Heine could write that "All our contemporary philosophers, perhaps without knowing it, look through lenses Baruch Spinoza has polished." Since then the Spinozist "Optik" has lost whatever transparency it once had, so that modern comment faces the question of substantive justification. Spinoza "in modern dress"—e.g., set-theoretic formalizations of Ethics 1 and 2—might turn out to have only the novelty of imperial clothing. On the other hand, Spinoza taken on what are commonly thought to be his own terms might well seem merely the relic of an opaque tradition.