Entity realism
Entity realism is a view in the philosophy of science. It says we should believe in parts of scientific theories only if those parts can be used to reliably produce real effects in the world. In particular, it argues that unobservable entities (like electrons) are real if scientists can routinely manipulate them to cause effects that can be studied independently. A famous saying from Ian Hacking is: “if you can spray them, then they are real.”
Because it emphasizes what experiments and instruments actually do, entity realism is also called instrumental realism or experimental realism. It is a realist stance, but a selective one: it doesn’t claim that theories as a whole are true or approximately true, only that certain entities mentioned by the theories are real because we can manipulate them.
Critics say it is too narrow—some real things can be observed but not easily manipulated—while others say it is too permissive, since successful manipulation might be coincidental or misleading. So it’s a realist view that accepts some unobservable entities as real without claiming the entire theory is true.
Entity realism is connected to the idea of referential realism, as discussed by Harre in 1986.
This page was last edited on 2 February 2026, at 03:56 (CET).