We shall find that well-grounded doctrine of Democritus of benefit to us, in which he shows that a tranquil state of mind is only possible if we devote relatively little time to private or public affairs, or at least to those that are too great for our strength. When a man busies himself with many duties, the day never passes so happily for him that he fails to encounter some problem, arising from a person or situation, which makes his mind ripe for anger. Just as a man hurrying through the busy districts of the city must collide with many people, and will inevitably lose his footing in some places, and be held back in others, and, in others still, be splashed, so in this activity of life, with all its variety and inconstancy, many hindrances, many causes for complaint cross our path. One man cheats our hopes, another postpones them, a third dashes them; our designs do not proceed as we had planned. No man finds Fortune so compliant that she responds on each occasion to his many overtures; it follows, therefore, that when a man finds that some of his plans have fallen out contrary to his wishes, he grows impatient with men and the world, and on the slightest of pretexts becomes angry, now with a person, now with his occupation, now with where he lives, now with his luck, now with himself. And so, in order that the mind can achieve peace, it must not be tossed about, or, as I said, worn out by activity in many enterprises, or ones that are demanding and place too great a strain on its powers. It is easy to fit light burdens to our shoulders, and to move them from one side to another without their slipping, but what has been placed on us by the hands of others we find hard to support, and owning defeat, we shed our load onto the next man; even while we stand beneath the baggage, we stagger, finding ourselves unequal to the burden.

Seneca, ‘On Anger’