Hypothetically speaking, is it really enough?

I wanted to bring up two things from the second to last (penultimate, you might say) paragraph from Newton's General Scholium in Book III. First, his use of the word "hypothesis" seems to be quite different from what we've seen this far. He says, "I do not contrive hypotheses. For whatever is not deduced from the phenomena is to be called a hypothesis, and hypotheses...have no place in experimental philosophy" (96). By "hypothesis," he seems to mean something like a "guess." In effect, he is saying, "I'm not going to guess at the reasons for my observations." He wants reasons, proofs. It's interesting that he says hypotheses don't have a place in experimental philosophy, because, at least as I learned it, modern scientific method involves starting with a hypothesis (in the form of an "if...then..." statement), which is then tested through experiments. The hypothesis is actually quite important for the whole process. Hypothesis in this sense seems not be exactly what Newton means, but not too far off, since in this sense it's sort of a "best, educated guess."

Second, he says, "And it is enough that gravity really exists, and acts according to the laws set forth by us...." According to the context, you could add "even though we don't really know what gravity is,..." to the beginning of that statement. My question to Newton and to the class is, "Is it really enough?" Sure, it's sufficient to explain and predict various phenomena, but I think Newton really wants to know what exactly gravity is. The quotation that Pesic uses (about Neewton on the beach) brings this out. Like all wise thinkers, he knew (or at least had an idea) how much he did not know.