It is certainly not the least charm of a theory that it is refutable; it is precisely thereby that it attracts the more subtle minds. It seems that the hundred-times-refuted theory of the "free will" owes its persistence to this charm alone; some one is always appearing who feels himself strong enough to refute it.
Friedrich NietzscheOne's own self is well hidden from one's own self; of all mines of treasure, one's own is the last to be dug up.
Friedrich NietzscheDoes not the discipline of the scientific spirit just commence when one no longer harbours any conviction?
Friedrich Nietzsche