The career of the philosopher Wittgenstein is a good example of the mystorical principle (from Nietzsche) of there being a point of intersection between the anecdote of life (the family story) and the aphorism of thought (the terms of one's career field). Wittgensteinr's biographer reported that a childhood memory to which the philosopher ascribed great significance was the broken plaster patch in the bathroom wall of his childhood home that the child Wittgenstein saw as a duck figure and that terrified him. As an adult, the optical illusion of the duckrabbit played an important role in Wittgenstein's theories.