The belief in truth begins with the doubt of all truths in which one has previously believed. 2, 20
Philosophic brains will ... be distinguished from others by their disbelief in the metaphysical significance of morality. 2, 29
You hold that sacrifice is the hallmark of moral action?—Just consider whether in every action that is done with deliberation, in the best as in the worst, there be not a sacrifice. 2, 30
It is more convenient to follow one's conscience than one's intelligence, for at every failure conscience finds an excuse and an encouragement in itself. That is why there are so many conscientious and so few intelligent people. 2, 33
All moralists are shy, because they know they are confounded with spies and traitors, so soon as their penchant is noticed. Besides, they are generally conscious of being impotent in action, for in the midst of work the motives of their activity almost withdraw their attention from the work. 2, 42
No one accuses without an underlying notion of punishment and revenge, even when he accuses his fate or himself. All complaint is accusation, all self-congratulation is praise. Whether we do one or the other, we always make some one responsible. 2, 44
We must know how to emerge cleaner from unclean conditions, and, if necessary, how to wash ourselves even with dirty water. 2, 44
The origin of morality may be traced to two ideas: "The community is of more value than the individual," and "The permanent interest is to be preferred to the temporary." The conclusion drawn is that the permanent interest of the community is unconditionally to be set above the temporary interest of the individual, especially his momentary well-being, but also his permanent interest and even the prolongation of his existence. 2, 46-47
We should not shrink from treading the road to a virtue, even when we see clearly that nothing but egotism, and accordingly utility, personal comfort, fear, considerations of health, reputation, or glory, are the impelling motives. These motives are styled ignoble and selfish. Very well, but if they stimulate us to some virtue—for example, self-denial, dutifulness, order, thrift, measure, and moderation—let us listen to them, whatever their epithets may be! 2, 48