Kierkegaard in The Sickness Unto Death:
A person can go on living fairly well, seem to be a human being, be occupied with temporal matters, marry, have children, be honored and esteemed — and it may not be detected that in a deeper sense this person lacks a self. Such things do not create much of a stir in the world, for a self is the last thing the world cares about and the most dangerous thing of all for a person to show signs of having. The greatest hazard of all, losing one’s self, can occur very quietly in the world, as if it were nothing at all. No other loss can occur so quietly; any other loss — an arm, a leg, five dollars, a wife, etc. — is sure to be noticed.
from Sextus Empiricus, Outlines of Pyrrhonism, book 1, section 12, translated by Benson Mates:
We always say that as regards belief (i.e., dogma) the Pyrrhonist’s goal is ataraxia, and that as regards things that are unavoidable it is having moderate pathè. For when the Pyrrhonist set out to philosophize with the aim of assessing his phantasiai – that is, of determining which are true and which are false so as to achieve ataraxia – he landed in a controversy between positions of equal strength, and, being unable to resolve it, he suspended judgment. But while he was thus suspending judgment there followed by chance the sought-after ataraxia as regards belief. For the person who believes that something is by nature good or bad is constantly upset; when he does not possess the things that seem to be good, he thinks he is being tormented by things that are by nature bad, and he chases after the things he supposes to be good; then, when he gets these, he fails into still more torments because of irrational and immoderate exultation, and, fearing any change, he does absolutely everything in order not to lose the things that seem to him good. But the person who takes no position as to what is by nature good or bad neither avoids nor pursues intensely. As a result, he achieves ataraxia. Indeed, what happened to the Pyrrhonist is just like what is told of Apelles the painter. For it is said that once upon a time, when he was painting a horse and wished to depict the horse’s froth, he failed so completely that he gave up and threw his sponge at the picture – the sponge on which he used to wipe the paints from his brush – and that in striking the picture the sponge produced the desired effect. So, too, the Pyrrhonists were hoping to achieve ataraxia by resolving the anomaly of phenomena and noumena, and, being unable to do this, they suspended judgment. But then, by chance as it were, when they were suspending judgment the ataraxia followed, as a shadow follows the body. We do not suppose, of course, that the Pyrrhonist is wholly untroubled, but we do say that he is troubled only by things unavoidable. For we agree that sometimes he is cold and thirsty and has various feelings like those. But even in such cases, whereas ordinary people are affected by two circumstances – namely by the pathé themselves and not less by its seeming that these conditions are by nature bad – the Pyrrhonist, by eliminating the additional belief that all these things are naturally bad, gets off more moderately here as well. Because of this we say that as regards belief the Pyrrhonist’s goal is ataraxia, but in regard to things unavoidable it is having moderate pathé.