Deducing the four sources of knowledge

My defense of the second premise of my modal-epistemic argument relies amongst others on the claim that (on the specific conception of knowledge used for the argument) there are no more than four sources of knowledge: logical proof, self-evident intuition, experience and testimony. Here is an interesting suggestion from L. Newton to deduce that these four sources of knowledge are indeed exhaustive. Knowledge is either from oneself or another. If it is from another, then it is from 1) testimony. If it is from oneself, it is either from 2) experience or from the intellect. If it is from the intellect, it is either 3) self-evident or 4) logically proven.