A few years ago, Katja Grace asked, why read old philosophy? Why read it in the original rather than from a textbook? And her answer is that by reading the originals (or at least direct translations of the originals), you are learning to think like that philosopher so that hopefully you will also be able to produce good philosophy.
I wouldn’t say that that’s wrong, but I’d add another reason: you’re building a personal relationship with the philosopher. When you read an autobiography, it’s not just to learn about the events in that person’s life. You’d be perfectly happy with a biography for doing that. But with an autobiography you’re also learning how they felt about and understood those events. It’s the same sort of curiosity that you might have when catching up with a friend.
Philosophy can be very much like an autobiography. Indeed, I’d say that it is often an autobiography of a person’s internal life. And I’d suggest that that’s the appeal of it. I don’t endorse Nietzsche’s philosophy, but I have some sympathy for him, and I want to see the world through his eyes.
It has gradually become clear to me what every great philosophy has hitherto been: a confession on the part of its author and a kind of involuntary and unconscious memoir […]