These poor fools bring everything they see and everything they feel into relationship with the overvalued idea which, projected outward in the shape of an hallucination, sounds to their ears like a spiritual echo and blinds their eyes like a vision. A lover acts essentially like this. That is why the world says of a person in love that he makes himself ridiculous. A handkerchief or a glove, or anything belonging to the beloved, becomes a fetich which can evoke the most ecstatic emotions. Anything that can be associated with love is overvalued. Another question involuntarily presents itself. Is love, in the form known as “being in love,” the only overvalued idea with which a normal person may be afflicted? Are there any other forms of “physiological insanity”--if we may use the term coined by Lower and subsequently imitated by Moebius? The answer to these questions is not difficult. A backward look teaches us what unspeakable evils overvalued ideas have wrought in man’s history. For overvalued ideas are sources of great danger. They are richly endowed with emotions and consequently lend themselves to suggestion more readily than almost any other idea. Bleuler has proved that suggestion is nothing but the transference of an emotion. And such overvalued ideas can be hurled with great suggestive force among the multitude and change the individual--and even whole communities--into a fool. That is how the psychoses of whole nations have arisen. The tremendous power of overvalued ideas can be understood if one thinks of the crusades, the witchcraft persecutions, hysterical epidemics, the Dreyfus affair, anarchism, etc. It is a sad fact that none of us can be free from overvalued ideas. In this sense there is really no difference between fools and healthy persons. Everyone of us bears within himself a hidden quantity of neurosis and psychosis. What saves us from the insane asylum is perhaps only the circumstance that we hide our overvalued ideas or that so many persons share our folly and that the multitude accepts it as wisdom. There are innumerable aphorisms, the crystallised precipitations of thousands of years, experience, that express this truth. “Every man has his little crack, his dross and his sliver.” (In the German saying the overvalued idea is compared to a splinter in the brain. An excellent metaphor!) “If you see a fool take hold of your own ears.” “You cannot name a wise man who was not guilty of some folly.” (The reader will find ample material on this subject in Dr. Moenkenmöller’s book on ‘mental disease and mental weakness in satire, proverb, and humour,’ published in 1907.) In other words: We all suffer from a false and subjective valuation of our ideas. We all drag overvalued ideas about with us.