Still, if you haven't passively heard of Latour by the time you got to your masters and then is prepared to say that he is a nobody which should not contend with what has already been discussed a thousand years ago, I feel that you don't really have the credentials to claim whether or not he is a serious contender, or what it is that has already been discussed in philsophy for a thousands years. Latour is very much a part of an important discussion in philosophy. Just look at his contributions to the philosophy of science for one.