From the outset, it’s clear who lost the “name game” here.
The scientific realist posits that it is the job of scientific theories to explain the causes of observable phenomena in terms of whatever may cause them. He includes unobservable entities in his consideration, as he believes firstly of course that such things may exist, and secondly that science does not consist only in predicting similar phenomena by forming a “law,” but also about knowing what it is that is occurring in such a transaction between the objects of study. In other words, it’s about finding out the whole truth.
Quite on the contrary is the position of the instrumentalist. However, the instrumentalist view does not go so far as the anti-realist, who says that there just plain aren’t any unobservable entities. Rather, the instrumentalist is agnostic as to whether or not there are such entities, and he avoids them in theorizing. He believes that it is enough for science merely to be able to predict the effects of observable events. Any statements made about things that cannot be sensed are regarded by him as almost altogether meaningless in themselves. Instead, they hold only an “instrumental” meaning for him; that is to say, he may see them as being useful for grounding a theory in. This might remind one of the pragmatism of William James, which said that “truth” is whatever is useful for thinking.
An example will help to illustrate these differences. The Higgs-Boson particle has not yet been directly observed, despite those successes in 2012 and 2013. The existence of this particle would provide an account for why certain particles have mass. The scientific realist is greatly interested in knowing whether or not there is such a particle, and it is these sorts of people who tend to want to build particle accelerators and telescopes. The instrumentalist is content with the “idea” of the Higgs-Boson, but he does not care if it really exists. It fills a gap that did not need to be filled. What the instrumentalist cares about is collecting enough data to understand that there is mass in certain kinds of things.
Instrumentalism is antithetical to the spirit of Christianity (and classical philosophy) as it bears on the motivation for natural scientific knowledge. We ought to want to know “what lies beneath,” because it reflects the beauty and wisdom of God… It is good for the soul to seek this kind of knowledge for its own sake, since that is one of the highest purposes of our existence. The “speciating principle” of man is his ability to reason and possess speculative knowledge, which therefore becomes primary in the determination of how he flourishes. Instrumentalism shucks this virtue and turns it into about gaining what is useful rather than what is good in itself.
Main image: The Very Large Array
By John Fowler – Flickr: VLA, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=23385127