“You will find, dear boy, on these chivalric adventures of yours, that manly courage and fortitude, even when bolstered by the fortunate possession of an enchanted sword such as Dastagerd, are not quite enough: one requires, as well, the use of logic, reason, deduction, and, in a word—intelligence!”

The Rebel (1951)

Variant: It's true that adventures are good for people even when they are very young. Adventures can get in a person's blood even if he doesn't remember having them.
Source: The Secret of Platform 13

The Dying Animal (2001)

Source: Styxx

What is Enlightenment? (1784)
Variant: Have the courage to use your own reason- That is the motto of enlightenment.
Source: Groundwork of the Metaphysics of Morals
Context: Enlightenment is man’s leaving his self-caused immaturity. Immaturity is the incapacity to use one's intelligence without the guidance of another. Such immaturity is self-caused if it is not caused by lack of intelligence, but by lack of determination and courage to use one's intelligence without being guided by another. Sapere Aude! Have the courage to use your own intelligence! is therefore the motto of the enlightenment.

Author's Blessing
Lamb: The Gospel According to Biff, Christ's Childhood Pal (2002)
Source: Practical Demonkeeping
Context: If you have come to these pages for laughter, may you find it.
If you are here to be offended, may your ire rise and your blood boil.
If you seek an adventure, may this song sing you away to blissful escape.
If you need to test or confirm your beliefs, may you reach comfortable conclusions.
All books reveal perfection, by what they are or what they are not.
May you find that which you seek, in these pages or outside them.
May you find perfection, and know it by name.

Wisdom and Innocence: A Life of G.K. Chesterton, Joseph Pearce
Misattributed