“In physics the truth is rarely perfectly clear, and that is certainly universally the case in human affairs. Hence, what is not surrounded by uncertainty cannot be the truth.”

“Scientists or thinkers who try to discover the truth cannot find that higher life by thinking alone, but their own life, spent in search for the truth and neglecting the physical living, is just that higher form of human existence.”

“truth is that which makes a people certain, clear, and strong.”

“One way or another, I think we are all destined to learn the same lessons in life. Universal truths are universal truths. They cannot be changed.”

“Our aim as scientists is objective truth; more truth, more interesting truth, more intelligible truth. We cannot reasonably aim at certainty. Once we realize that human knowledge is fallible, we realize also that we can never be completely certain that we have not made a mistake.”

“To love truth for truth's sake is the principal part of human perfection in this world, and the seed-plot of all other virtues.”