Of all Psychology’s topics the one perennially fascinating the general public is ‘Personality’, for here Psychology most closely resembles such fortune-telling and personal advice-giving predecessors as astrology, physiognomy and phrenology. What people most desire from an expert on human nature is information about themselves, and even if their destinies cannot be divined this expert should at least be able to diagnose personal strengths, weaknesses, flaws and virtues, and advise on how to live with them. Put more succinctly, they yearn to place themselves in the spectrum of humanity at large. Popular ambivalence about Psychology notwithstanding, when it comes to ‘personality tests’ there is a large and avid market. This apparent continuity with pre-Psychological traditions is no illusion, as we will see. But first we must consider the word ‘personality’ itself.