But have you ever asked yourselves sufficiently how much the erection of every ideal on earth has cost? How much reality has had to be misunderstood and slandered, how many lies have had to be sanctified, how many consciences disturbed, how much "God" sacrificed every time? If a temple is to be erected a temple must be destroyed: that is the law - let anyone who can show me a case in which it is not fulfilled! - Friedrich Nietzsche, The Genealogy of Morals
Quotes are a unique enough medium of expression that I'm interested in viewing quotes that people have found collectable, emotionally impactful, useful, memorable, or otherwise noteworthy - perhaps others are similarly interested. To clarify, these need not be even remotely related to rationality. I'm hijacking the mandates traditionally used for the Rationality Quotes thread, with a few modifications:
Please post any meta discussion in the top-level comment named "Meta".