Animal Instinct and Self-Preservation — Letters from a Stoic

Every living thing, from the moment of birth, has a feel for what belongs to its constitution and what does not. Letter 121 makes the case for what Seneca calls 'self-love' in the original sense, not vanity, but the basic orientation of every creature toward its own preservation and proper functioning. A new-born animal does not need to be taught to protect itself; it already knows, by some faculty prior to reason, what is appropriate to it.

The foal is not told to avoid the wagon wheel; the chick flees the hawk without instruction. This is not instinct as mere mechanism, it is, Seneca argues, the first form of self-knowledge: knowing what kind of thing you are. The letter uses this observation to defend the philosophical investigation of nature against the objection that it has nothing to do with character.

On the contrary: you cannot know what character is desirable until you have discovered what is best suited to man. You cannot learn what to do and what to avoid until you have learned what you owe to your own nature.

Dumb beasts, sluggish in other respects, are clever at living. The human animal, gifted with reason, has far more capability, if only it chooses to use it.