Stevenson's ""interdisciplinary"" primer analyzes seven systems of thought, examining Plato, Christianity, Marx, Freud, Sartre, Skinner and Lorenz according to their theories of the universe, their statements on the nature of man, their diagnoses of what is wrong with him and their prescriptions for putting it right. Inventing the discipline of ""applied philosophy,"" Stevenson, a British professor, subjects each system to the rigor of his standards: is it ""closed,"" that is, can it only deal with its detractors ad hominem (like Marxism and Christianity)? are the normative judgments separable from the descriptive ones? and, most important, can it withstand the test of the verification principle (can it be empirically evaluated)? These are decidedly arbitrary yardsticks. The meaning and roots of ""applied philosophy"" are muddled, at times incomprehensible. Philosophy -- and all model making -- is much more than science; it is a structure of subjective meaning. The author's dogmatic positivism (on Sartre: ""Cannot someone choose not to want to become an object. . . ?"") distorts these thinkers, and springs from his own ""scientific"" bias. Simplistic and limited.