Abstract
Assuming for the sake of discussion that there is an external world, The "core" thesis of scientific realism is that some of our empirical beliefs (including the so-Called theoretical beliefs) succeed in correctly describing, In some important measure, The external world. Classical scientific realism also asserts that we are able to say justifiably just "which" of our beliefs so succeed in correctly describing the external world. This paper does not examine this last claim. Rather it seeks to defend the core thesis of scientific realism and will assume (for reasons of limited space) the existence of an external world. In defending the core thesis, This paper returns to and defends the explanationist defense which asserts that the core thesis offers the best available explanation for the long-Term predictive success of "some" empirical or scientific hypotheses. The defense consists in examining and rejecting all available alternative explanations as well as all objections to the explanationist defense as offered in this paper.