“From the midst of the flat plain of human reason, there arises the terrible, fire-spewing mountain of genius.”

I Think I'll Sit This One Out (1939)
Context: Justice alone knows liberty, equality, and fraternity, and justice is a human virtue arising from man's human capacity to reason. We cannot make sense out of justice by looking at the moon or taking dope or building battleships. We can make sense out of justice by using our reason to discover that justice, like wisdom, is better than rubies.

Lectures on Rhetoric and Belles Lettres (1784), Lecture I: Introduction.

Source: Halakhic Man (1983), pp. 83-84

The Philosophical Emperor, a Political Experiment, or, The Progress of a False Position: (1841)
Context: To jump occasionally into the pit is common to all who visit the mountain, and to some who keep on the plain; but the madness to which I have alluded consists in rapid alternations from the mountain to the pit, annoying all persons who are forced, by friendship or consanguinity, to consort with the unfortunate maniacs. To remain permanently either on the pinnacle or in the abyss is deemed a species of the same disorder, though not so common.

2011, Tucson Memorial Address (January 2011)
Context: Scripture tells us that there is evil in the world, and that terrible things happen for reasons that defy human understanding. In the words of Job, "when I looked for light, then came darkness." Bad things happen, and we must guard against simple explanations in the aftermath.