Why do some philosophers argue that theoretical terms such as electron refer to real entities?

Philosophers who argue that theoretical terms like "electron" refer to real entities are known as scientific realists. They contend that science aims to provide a literally true account of the world, including aspects that are not directly observable.12

The primary arguments for this position include:

• Explanatory Power: Realists argue that one cannot make sense of scientific explanations—such as why elements combine in specific ways—without acknowledging the reality of unobservable entities like electrons, shells, and nuclei.1
• The "No Miracles" Argument: This influential line of reasoning suggests that the systematic success of scientific theories—such as the ability to compute reaction energies with extraordinary accuracy—would be a "coincidence of cosmic proportions" or a "miracle" if those theories were not at least approximately true.32
• Independent Verification: Philosophers like Wesley Salmon noted that when multiple, independent methods of determining the values of unobservable quantities yield the same result, it is highly improbable that these entities do not exist.3
• Rejection of the Observational Divide: Many realists argue there is no sharp, principled distinction between observable and unobservable entities, noting that the range of what is "observable" expands with technology, such as microscopes.32