Education:

"The power of instruction is seldom of much efficacy except in those happy dispositions where it is almost superfluous"
   (Gibbon)

Education must have two foundations - morality as a support for virtue, prudence as a defense for self against the vices of others. By letting the balance incline to the side of morality, you only make dupes or martyrs; by letting it incline to the other, you make calculating egoists.
   (Chamfort)

Ends:

"Not every end is a goal."
   (Nietzsche)

Equality:

"Non omnia possumus omnes - We are not all capable of everything."
   (Virgil)

Error:

"One seldom rushes into a single error."
   (Nietzsche)

"Man does not live long enough to profit from his faults."
   (La Bruyère)

"More dangers have deceived men than forced them."
   (Bacon)

"Fallor, ergo sum."
   (St. Augustine)

Evidence:

"A wise man proportions his belief to the evidence."
    (David Hume, An Enquiry Concerning Human Understanding)

"It is wrong always, everywhere, and for anyone, to believe anything upon insufficient evidence"
   (W.K. Clifford, The Ethics of Belief)

Evil:

"The only thing necessary for the triumph of evil is for good men to do nothing."
    (Edmund Burke)

"A person may cause evil to others not only by his actions but by his inaction, and in either case he is justly accountable to them for the injury."
    (John Stuart Mill, On Liberty)

"Yes, though I walk through the valley of the shadow of death, I will fear no evil"
   (Bible - Psalms)

"Remember not the sins of my youth, nor my transgressions."
   (Bible - Psalms)

"Eschew evil, and do good; seek peace, and ensue it."
   (Bible - Psalms)

Existence:

"Everything existing in the universe is the fruit of chance and necessity."
   (Democritos)

"Nothing exists except atoms and empty space; everything else is opinion."
   (Democritos)

Experience:

"Experience is only half of experience."
   (Goethe)

"Experience is not what happens to a man. It is what a man does with what happens to him."
   (Aldous Huxley)

"Few men are worthy of experience. The majority lets it corrupt them."
   (Joubert)

"Experience is the name everybody gives to his mistakes."
   (Wilde)

"If a man has character, he also has his typical experience."
   (Nietzsche)

"To most men, experience is like the stern lights of a ship, which illumine only the track it has passed."
   (Coleridge)