Synopsis The present book as its title suggests is general in nature. But its main emphasis is on classification of men in general and that is why it dwells mainly on intelligence. Advocate of an associationistic psychology which emphasized the experiential basis of all human knowledge, Mill was openly contemptuous of the nativist argument, writing, “Of all vulgar modes of escaping from the consideration of the social and moral influences on the human mind, the most vulgar is that attributing the diversities of human conduct and character to inherent original natural differences.” Consistent with these beliefs, Mill argued that the greatest differences between races and sexes, as well as between individuals, are due to environmental and circumstantial factors. Sometimes called “the patron saint of liberty”, Mill and his arguments are still widely cited by supporters of the nurture side in the nature-nurture controversy.