Blaise Pascal, Pensées #329:
Man is neither angel nor beast; and the misfortune is that he who would act the angel acts the beast.
The first half of the thought is unexceptionable: man is indeed neither angel nor beast, but, amphibious as he is between matter and spirit, a hybrid and a riddle to himself.
The second half of Pascal's thought, however, is unfair to the beasts. No beast can act the beast the way a man can. No beast is bestial in the way a man can be bestial. The difference is that while the beast acts according to his nature, man freely degrades himself contrary to his nature. Having done so, he allows his freely indulged passions to suborn his intellect: he constructs elaborate rationalizations of his self-degradation.
It is not our animality that corrupts us but our free misuse of our animality, a misuse that derives from our spirtuality.