ABSTRACT
The realist places great emphasis on the power of scientific theories to explain the phenomena that they describe. Indeed, for many, explanation is a primary goal of the scientific enterprise. The basic principles of chemistry, which describe how atoms of different elements in certain fixed ratios combine to form molecules of different compounds which we can identify in the natural world (such as carbon dioxide, water and salt), are now applied in every part of science, from astrophysics to cellular biology. So most of the explanations that we have for natural phenomena involve reference to theoretical and unobservable entities. Realists argue that the truth or approximate truth of a hypothesis is a necessary condition for it to be part of a genuine scientific explanation; in other words, explanation requires more than mere empirical adequacy. Realists therefore claim that explanation in science is unintelligible from the perspective of constructive empiricism.
