On Duties 1.11 — Cicero (on the Stoics)

Cicero (on the Stoics), On Duties 1.11

First of all, Nature has endowed every species of living creature with the instinct of self-preservation, of avoiding what seems likely to cause injury to life or limb, and of procuring and providing everything needful for life—food, shelter, and the like. A common property of all creatures is also the reproductive instinct (the purpose of which is the propagation of the species) and also a certain amount of concern for their offspring. But the most marked difference between man and beast is this: the beast, just as far as it is moved by the senses and with very little perception of past or future, adapts itself to that alone which is present at the moment; while man—because he is endowed with reason, by which he comprehends the chain of consequences, perceives the causes of things, understands the relation of cause to effect and of effect to cause, draws analogies, and connects and associates the present and the future—easily surveys the course of his whole life and makes the necessary preparations for its conduct.