Also known as Pessimistic induction from the history of science
In the past, we have had scientific theories which were successful but did not furnish approximately true descriptions of the world. Our current best scientific theories are successful, but eventually we will also realize that they do not furnish approximately true descriptions of the world either, as talked about in Kuhn-on-crisis-and-scientific-revolutions.
Historical examples of successful theories which do not furnish approximately true descriptions of the world:
- paradigm-shift-from-phlogiston-to-oxygen we thought that phlogiston was the best explanation in combustion theories but it was then replaced by oxygen. Oxygen could also be one day replaced by another theory; the fact that is the best theory right now, that does not mean it is an accurate description
- humors in medicine
- caloric vs heat In 18th century thermodynamics, heat was explained by effect of flow of fluid caloric from hot bodies to cold bodies. An example of a successful explanation in caloric theory =
This argument shows that all we actually should care about is the theory that works best for practical purposes at a given time. It also shows that realism about entities is difficult because there are so many entities we thought existed that we know believe no longer did.
From what i understand this argument is using the intuition that best explanations are replaced at one point and we eventually realize that they do not accurately describe the world. However, the fact that our “best” explanations can be replaced does not mean that we should support anti-realism. Could we say that we are getting closer and closer to the truth? Phlogiston was replaced by oxygen because anomalies arose and oxygen was a better explanation to explain those anomalies. In the caloric theory, while caloric does not exist, there was continuity across the theories, energy flows instead of a fluid substance. There is something we were getting right in the old theories that gave it its success and now we have better theories that have some continuity from the old. This leads onto structural-realism