This treatise published in 1689 was listed in Good Reading's "100 Significant Books." It's a work of epistemology--the branch of philosophy that examines knowledge. Rejecting Descartes' argument of innate principles, Locke argues that humans at birth are a blank slate written on by experience. Locke argues that innate ideas can't exist since by their nature they'd be universal, and there is no knowledge everyone agrees upon. I'm not sure given human nature I agree. I know that as different as human cultures and individuals might be, there are some constants, and even linguists think that's reflected in the structure of language. Many scientists and philosophers seem to try to argue for one single cause for things. I see no reason to believe identity and ideas couldn't come from both a hard-wired human nature and experience--that is, both nature and nurture. It's not that I disagree that what knowledge we have can only come from the senses and the use of reason to interpret it. That makes sense to me--but that doesn't mean I find Locke's particular line of argument completely convincing. And particularly because epistemology lies at the root of philosophy, it has consequences for ethics and politics. Locke is associated with the libertarian principles of the American Revolution. Thomas Jefferson cribbed much of the American Declaration of Independence from Locke's Two Treatises of Government. If humans are blank slates to be written on, in one way that can be very heartening and optimistic--a chance to make the world anew. But it also tempts people into totalitarian schemes, thinking humans can be twisted into whatever shapes they will. I have other doubts about Locke's arguments. If we only know things by experience, and there are no universals, how can Locke argue in Book II that it is a "certain and evident truth" that there is a God? But then even in the dedication and "Epistle" to the reader there seemed to be a nervousness that the entire thrust of his argument is atheist. Methinks here Locke was not being intellectually honest or at least not intellectually consistent--and given the intolerance of his times I hardly blame him. Moreover I really don't see the usefulness of dividing ideas and things into simple and complex, primary and secondary qualities. But the importance of the ideas in this essay I do not doubt. And despite the difficulties of the subject, I found Locke fairly lucid--it probably helped I was exposed to excerpts from this essay before in school. I don't know that I'd call it enjoyable reading, and I think this could be more succinct (even Locke admits that in his opening remarks.) But reading it is useful to know to understand not just the subjects it touches upon, but its influence on history.