He, who knows how to distinguish between true and false, must have an adequate idea of true and false.
Baruch SpinozaWhatsoever is contrary to nature is contrary to reason, and whatsoever is contrary to reason is absurd.
Baruch SpinozaSimply from the fact that we have regarded a thing with the emotion of pleasure or pain, though that thing be not the efficient cause of the emotion, we can either love or hate it.
Baruch SpinozaI should attempt to treat human vice and folly geometrically... the passions of hatred, anger, envy, and so on, considered in themselves, follow from the necessity and efficacy of nature... I shall, therefore, treat the nature and strength of the emotion in exactly the same manner, as though I were concerned with lines, planes, and solids.
Baruch Spinoza