Divide each difficulty into as many parts as possible for a better solution.

I think, therefore I am.

Once in one's life, everything should be called into doubt.

I think, therefore I am.

The wise man is free from passions, not because he does not feel, but because his judgments are correct.

-- Chrysippus of Soli

Neither a man nor a crowd nor a nation can be trusted to act humanely or to think sanely under the influence of a great fear.

-- Bertrand Russell

I have striven not to laugh at human actions, not to weep at them, nor to hate them, but to understand them.

-- Benedictus de Spinoza

The divine law commands rational consideration of existing things and reflection upon them.

-- Averroes

The pleasant life is produced not by endless drinking and revelry but by sober reasoning.

-- Epicurus

The legal subordination of one sex to another is wrong in itself, and now one of the chief hindrances to human improvement.

-- John Stuart Mill