"The summer of 1959: ... My biggest concern was summer employment. Many friends who were engineering students had found lucrative summer jobs that paid well above the minimum wage. My prospects were bleak: I was a philosophy major. I did not find in the newspaper a single want ad calling for philosophers. My only real option was a job for unskilled labor paying the minimum wage. Even at that I was delighted to be offered work in the maintenance department of a hospital.
When the foreman heard I was a philosophy major, he handed me a broom and said, “Here, you can think all you want while you’re leaning on the broom.”

During my first week on the job, I was reaching the end of my sweeping territory. My zone ended where the main hospital driveway intersected the parking lot of the nurses’ home. I noticed another man sweeping the adjacent parking lot. He greeted me, and we exchanged names and pleasantries. When I told him I was a college student, he asked what I was studying. When I said philosophy, his face brightened and his eyes lit up. He fired a barrage of questions at me, inquiring about Descartes, Plato, Hegel, Kant, Kierkegaard, and others. I was astonished at this man’s knowledge. He obviously knew far more about philosophy than I did.
My new friend was from Germany. He had his Ph.D. in philosophy and had been a professor of philosophy in Berlin. When Adolf Hitler came to power, the Nazis were not content to find a “final solution” for Jews and Gypsies. They also sought to eliminate intellectuals whose ideas were at odds with the “values” of the Third Reich. My friend was removed from his position. When he spoke out against the Nazis, his wife and all but one of his children were arrested and executed. He escaped from Germany with his young daughter.

I mused on something else that morning, which is why I am recounting the tale here. I was pushing a broom because I lived in a culture that sees little value in philosophy and gives scant esteem to those who pursue it. My friend was pushing a broom, on the other hand, because he came from a culture that gave great weight to philosophy. His family was destroyed because Hitler understood that ideas are dangerous. Hitler so feared the consequences of my friend’s ideas that he did everything possible to eliminate him -- and his ideas.

• Chapter 2: Plato
• Chapter 3: Aristotle
• Chapter 4: Augustine
• Chapter 5: Thomas Aquinas
• Chapter 6: Rene Descartes
• Chapter 7: John Locke
• Chapter 8: David Hume
• Chapter 9: Immanuel Kant
• Chapter 10: Karl Marx
• Chapter 11: Soren Kiekegaard
• Chapter 12: Friedrich Nietzsche
• Chapter 13: Jean-Paul Sartre
• Chapter 14: Darwin and Freud
• Conclusion: Gilson's Choice

Epicureans sought to escape the “hedonistic paradox”: The pursuit of pleasure alone ends in either frustration (if the pursuit fails) or boredom (if it succeeds). Both frustration and boredom are kinds of pain, the antithesis of pleasure. Thus Epicureans sought not the maximum pleasure but the optimum pleasure. They concluded that a wise man’s diet of bread and water will more likely bring happiness than a glutton’s diet of gourmet food.

Marx predicted that the condition of workers in capitalist societies would become steadily worse. The poor would become poorer while the rich would become richer, until the masses would revolt and take over the means of production for themselves. This was Marx’s greatest error. He assumed the myth that the rich can only get rich at the expense of the poor. One man’s gain must spell another man’s loss... No economic system has been as effective as capitalism in raising the human standard of living.

• "Consequences of Ideas: Understanding the Concepts that Shaped our World" by R.C. Sproul. Amazon. Logos.