“Thought must be divided against itself before it can come to any knowledge of itself.”

“Grief can take care of itself, but to get the full value of joy you must have somebody to divide it with.”

“[A] nation must ravage itself before foreigners can ravage it, a man must despise himself before others can despise him.”

“He whose wisdom surpasses that of all philosophers, has declared that 'a house divided against itself cannot stand”

“it is clear that we must trust what is difficult; everything alive trusts in it, everything in Nature grows and defends itself any way it can and is spontaneously itself, tries to be itself at all costs and against all opposition. We know little, but that we must trust in what is difficult is a certainty that will never abandon us; it is good to be solitary, for solitude is difficult; that something is difficult must be one more reason for us to do it.”

“For successful education there must always be a certain freshness in the knowledge dealt with. It must be either new in itself or invested with some novelty of application to the new world of new times. Knowledge does not keep any better than fish. You may be dealing with knowledge of the old species, with some old truth; but somehow it must come to the students, as it were, just drawn out of the sea and with the freshness of its immediate importance.”