In an interview on Ideas that Matter

What does Aristotle say about being good then?

Aristotle’s answer to the question is based on the idea that we call “good” what relates to the distinguishing function of a thing. So a knife is a good knife if it cuts well. Analogously, when we say that a person is good, what we mean is that he lives according to the most distinctive thing about human beings, which is the faculty of reason. If you live a considered life you will have what Aristotle called “eudaimonia”. The usual translation of eudaimonia is happiness, but that concept is rather too thin. It really means “flourishing” and “achievement”.

What happened to the idea of the “public philosopher”?

The idea that philosophy belongs to every educated person has been diminished as a result of the professionalization of the academy over the last century or so. The result has in many ways been negative; philosophy has developed into an esoteric pursuit marked by technical jargon and over-fine distinctions, rather like scholastic philosophy. If you go back to Hume, Locke or Descartes, you find that they weren’t writing for professionals in university, they were writing for their educated peers. Every educated mind should be reflective and engaged with the great questions.

Kant, the author of your next choice, is surely no “public philosopher”?

True, the Critique of Pure Reason is not a book for the general public (unless they work very hard at it). But the contribution it makes to philosophy is fascinating, although I don’t think that it’s right in many of its details. It was a powerful effort to make sense of the relationship between thought and the world. In my own more technical work in philosophy I’m fascinated by the same question Kant is asking. It is one of the most fundamental questions in philosophy: how do thought, experience, language and theory-formation relate to the world out there?

What does he argue?

Critique of Pure Reason is an effort to show that when we try to apply the concepts of our ordinary perceptual experience to what lies beyond sense perception, they run wild, like cogs not engaged with each other. All the concepts we use in thinking about the world, for example unity and causality, are only the properties of our ordinary experience. When we start thinking about things that lie beyond the bounds of our senses, and try to apply these concepts to them, we get into trouble.