Error has made man so deep, sensitive, and inventive that he has put forth such blossoms as religions and arts. Pure knowledge could not have been capable of it.
For myself, I like a universe that, includes much that is unknown and, at the same time, much that is knowable. A universe in which everything is known would be static and dull, as boring as the heaven of some weak-minded theologians. A universe that is unknowable is no fit place for a thinking being. The ideal universe for us is one very much like the universe we inhabit. And I would guess that this is not really much of a coincidence.
The science [geometry] is pursued for the sake of the knowledge of what eternally exists, and not of what comes for a moment into existence, and then perishes.
There is nothing so charming as the knowledge of literature; of that branch of literature, I mean, which enables us to discover the infinity of things, the immensity of Nature, the heavens, the earth, and the seas; this is that branch which has taught us religion, moderation, magnanimity, and that has rescued the soul from obscurity; to make her see all things above and below, first and last, and between both; it is this that furnishes us wherewith to live well and happily, and guides us to pass our lives without displeasure and without offence.
Lastly, I would address one general admonition to all: that they consider what are the true ends of knowledge, and that they seek it not either for pleasure of the mind, or for contention, or for superiority to others, or for profit, or fame, or power, or any of these inferior things: but for the benefit and use of life; and that they perfect and govern it in charity.