In an animated conversation, I often see the face of the person with whom I am speaking so clearly and sharply defined before me, according to the thought he expresses, or which I believe to be evoked in his mind, that the degree of distinctness far exceeds the strength of my visual faculty—the delicacy of the play of the muscles and of the expression of the eyes must therefore be imagined by me. Probably the person put on quite a different expression, or none at all.
Potential Pathology: Given the ongoing discussion about Nietzsche's health (migraines, suspected bipolar disorder, and later mental collapse), this anecdote raises concerns about his mental stability. It suggests a blurring of the line between internal thought processes and external reality, which became a defining feature of his later life.
