Entity realism

An occasional controversy in science is whether some theoretical &ldquo;entity&rdquo; is really real, or just a mathematical/modeling convenience. Ian Hacking has an interesting and eminently pragmatic answer that goes under the name &ldquo;entity realism.&rdquo; I believe him. The positron (positively charged electron) was originally theorized by Paul Dirac as an implication of Dirac equation ,…