Book 1 · Section 31

(31) Why does Moses say that the serpent was more cunning than all the beasts of the field? (#Ge 3:1). One may probably affirm with truth that the serpent in reality is more cunning than any beast whatever. But the reason why he appears to me to be spoken of in these terms here is on account of the natural proneness of mankind to vice, of which he is the symbol. And by vice I mean concupiscence, inasmuch as those who are devoted to pleasure are more cunning, and are the inventors of stratagems and means by which to indulge their passions. Being, forsooth, very crafty in devising plans, both such as favour pleasure and also such as procure means of enjoying it. But it appears to me that since that animal, so superior in wisdom, was about to seduce man, it is not the whole race that is here meant to be spoken of as so exceedingly wise, but only that single serpent, for the reason above mentioned.