Adam Smith's Wealth of Nations
Or An Inquiry into the Nature and Causes of the Wealth of Nations, as it seems to be called. I read this a couple of years ago (another illustration of the benefits of free out-of-copyright books for e-readers) but with all the Corbynomics kerfuffle it seemed a good time to mention it.
I read it in the spirit of Know Your Enemy, since Adam Smith seems to get blamed/credited with everything free market from Thatcher onwards that I oppose, but I was pleasantly surprised. His views were not quite what I expected, I even agreed with a fair bit of it (though some might have worked with a smaller population and a different system of banking etc but isn't applicable today. And sometimes he seems almost naive in thinking people will do what's fair or best for the country rather than what provides most short-term advantage to themselves).
He's by no means a socialist but the provision of a living wage and progressive taxes seem to fall naturally out of his style of pragmatism. He doesn't have much time for the idle rich, or greedy merchants who whisper in government ears to make sure their own interests come before those of the nation. Which I'm sure would come as a great disappointment to half the people who point to him as the foundation of their economic beliefs, but haven't actually read this book.
What's the moral of this tale? That Tories aren't always as bad as you think? Well, I'm not sure I'd go that far... However, go to the original source whenever possible, that could be one lesson to learn. Like reading Corbyn's economic policy for yourself instead of believing the doom merchants.