You should be especially careful when associating with one of your former friends or acquaintances not to sink to their level; otherwise you will los… - Epictetus

Kein Mensch, der in Furcht oder Sorge oder Chaos lebt, ist frei, aber wer sich von Sorgen, Furcht und Chaos befreit, wird dadurch auch aus der Sklaverei befreit.

If someone handed your body over to a passerby, you would be annoyed. Aren’t you ashamed that you hand over your mind to anyone around, for it to be upset and confused if the person insults you?

The first and most important field of philosophy is the application of principles such as “Do not lie.” Next come the proofs, such as why we should not lie. The third field supports and articulates the proofs, by asking, for example, “How does this prove it? What exactly is a proof, what is logical inference, what is contradiction, what is truth, what is falsehood?” Thus, the third field is necessary because of the second, and the second because of the first. The most important, though, the one that should occupy most of our time, is the first. But we do just the opposite. We are preoccupied with the third field and give that all our attention, passing the first by altogether. The result is that we lie – but have no difficulty proving why we shouldn’t.