Reddit reviews Plato: A Very Short Introduction

A philosopher once said that "The safest general characterization of the European philosophical tradition is that it consists of a series of footnotes to Plato".

He wasn't being completely serious, but it's not far from the truth. If you want to understand Western philosophy, read Plato. In fact I would push it a step back and say that if you want to understand the roots of Western philosophy, look at the "debate" between Heraclitus and Parmenides, which is a lot of what Plato is concerned with.

These three thinkers aren't easy to just jump right in to though, even for people who have grown up in the tradition. I haven't read any introductory work on Plato, but I'll bet that this would be a good starting point. He's really the key to the whole enterprise, because a lot of what other Western philosophers are saying is in response to him, however indirectly.

Socrates doesn't have any writings.

Very Short Introductions

Socrates

Plato

Aristotle

Routledge Philosophers

The Socrates entry in this series won't be released until later this year

Plato

Aristotle

Alternatively, just read the first volume in Kenny's A New History of Western Philosophy.