In Locke's inconsistency is also in theory. As we have seen in the relevant chapter, Locke says, on the one hand, that since the soul in all its thoughts and reasonings no immediate object but its own ideas, which alone she contemplates and can contemplate, it is evident that our knowledge refers only to them. On the other hand, "knowledge is the perception of the agreement or disagreement of two ideas." Nevertheless, he argues that we have three types of knowledge about the real existence: intuitive - on our own, conspicuous - the existence of God and sense - of things, a sense of the data. Simple ideas, he says, are the product of things operating in our brain naturally. As he learns this, he does not explain. It's definitely more than "agreement and disagreement of two ideas."