(For book recommendations particularly relating to political philosophy, history, and liberal education, see "Suggestions for Further Reading" on the "Introduction to Political Philosophy" page. This separate page is for worthy books having no particular connection to political science. I have particularly singled out books that offer unconventional insight on other disciplines, including psychology, economics, and biology):

Ellis, John. "Literature Lost: Social Agendas and the Corruption of the Humanities" (Yale Univ., 1997). The best critique yet published of the way in which the academic study of literature has been ruined by its politicization.

Jonas, Hans. The Phenomenon of Life: Towards a Philosophical Biology (Harper and Row, 1966). Essays by a distinguished philosophical scholar who was concerned with uncovering the continuity of human and animal life through their shared display of purposiveness. Like Lorenz (below), Jonas was interested in how animals share in human purposiveness rather than in trying to explain human life away as explicable in "merely" animal, i.e., materialistic, terms.

Lorenz, Konrad. "King Solomon's Ring: New Light on Animal Ways” (Crowell, 1952). Fascinating account of animal behavior by a leading student of the subject, showing that animals in the wild behave in much more interesting ways than you'd ever guess from seeing them caged in a zoo!

Rhoads, Steven. "The Economist's View of the World"  (Cambridge Univ., 1985). The first two parts of this outstanding book aim to demonstrate the utility of economic analysis for resolving critical public policy questions, and are particularly directed to political "liberals" who underestimate the value of market-based analyses and solution. The last part, conversely, stresses the limitations of economic analysis, i.e., its unsuitability for resolving critical moral issues (such as those relating to religion and sexuality) - so as to correct the arguments of free-market "conservatives" and libertarians who exaggerate the capacity of economics. Of value for persons of all political persuasions!

Straus, Erwin. "Phenomenological Psychology" (Basic Books, 1966). Collected essays by a truly philosophical psychologist - much more profound than Freud! (See also his "The Primary World of the Senses: A Vindication of Senory Experience.")