R.C. Sproul is known as a pastor and theologian, but he is also well versed in the field of philosophy. In The Consequences of Ideas, Sproul guides his readers through the most important thinkers of history. Some of them are Christians (Augustine, Aquinas, Kierkegaard), but many of them are not (Plato, Aristotle, Hume, Marx, Nietzsche, Darwin). Though only 200 pages and easy to read, Sproul successfully surveys 2,500 years of philosophy.