One method to distinguish between the things we think are real, but are not, is to see what you can change by pretending things are actually like X. Whatever do

One method to distinguish between the things we think are real, but are not, is to see what you can change by pretending things are actually like X. Whatever doesn't change - that's evidence that's "real". To paraphrase, "reality is that which, when you pretend otherwise, continues to be the way it is."