Scientific realism
Scientific realism is the view that the universe described by science is real regardless of how it may be interpreted. A believer of scientific realism takes the universe as described by science to be true (or approximately true), because of their assertion that science can be used to find the truth (or approximate truth) about both the physical and metaphysical in the Universe.
Within philosophy of science, this view is often an answer to the question "how is the success of science to be explained?" The discussion on the success of science in this context centers primarily on the status of unobservable entities apparently talked about by scientific theories. Generally, those who are scientific realists assert that one can make valid claims about unobservables (viz., that they have the same ontological status) as observables, as opposed to instrumentalism.
Scientific realism is related to much older philosophical positions including rationalism and metaphysical realism. However, it is a thesis about science developed in the twentieth century. Portraying scientific realism in terms of its ancient, medieval, and early modern cousins is at best misleading.
Scientific realism is developed largely as a reaction to logical positivism. Logical positivism was the first philosophy of science in the twentieth century and the forerunner of scientific realism, holding that a sharp distinction can be drawn between theoretical terms and observational terms, the latter capable of semantic analysis in observational and logical terms.
Logical positivism encountered difficulties with:
These difficulties for logical positivism suggest, but do not entail, scientific realism, and led to the development of realism as a philosophy of science.
Realism became the dominant philosophy of science after positivism.[2]: 70 Bas van Fraassen in his book The Scientific Image (1980) developed constructive empiricism as an alternative to realism. He argues against scientific realism that scientific theories do not aim for truth about unobservable entities.[3] Responses to van Fraassen have sharpened realist positions and led to some revisions of scientific realism.