This is the fourth and final part of Kreeft’s four-volume history of philosophy . . . on ancient, medieval, modern, and contemporary philosophy. Kreeft focuses on the "big ideas” that have influenced present people and present times, and includes relevant biographical data, proportionate to its importance for each thinker. Moreover, the aim of the work is to stimulate philosophizing, controversy, and argument. It uses ordinary language and logic, not jargon and symbolic logic, and it is commonsensical (like Aristotle) and existential in the sense that it sees philosophy as something to be lived and experienced in life. Philosophy, after all, is not about philosophy but reality . . . about wisdom, life and death, good and evil, and God. Kreeft seeks to be simple and direct and clear. But it is not dumbed down and patronizing. It will stretch the reader, but it is meant for beginnings, not just scholars. It can be used for college classes or do-it-yourselfers. It emphasizes surprises; remember, "philosophy begins in wonder.” And it includes visual aids: charts, cartoons, line drawings, and drawings of philosophers.