Among the many tools of the mind at the philosopher’s disposal, the test of self-reference is one of the most fundamental, subtle, and direct. I have utilized it myself in past arguments (here). In summary, the test is one of retorsion: you turn back the meaning of what a speaker says or claims upon the speaker himself, his activity of speaking, or even the conditions of environment or universe which would allow him to speak. The test is failed by way of a performative self-contradiction, when the meaning of what one claims undermines one’s ability to make such a claim or expect that it be accepted by one’s audience. The results of the test are primarily negative, but from the negative effects one can usually glean positive clues and insights based upon how exactly the test was failed.
The application of this test of self-reference in the area of the philosophy of science I learned from Richard F. Hassing (my dissertation director at CUA). Worthwhile viewing in his lecture summarizing the exemplary use of the test of self-reference by Hans Jonas. Especially interesting is Hassing’s conclusion, which I paraphrase: The existence of true human freedom (the ability to have rationally chosen otherwise) is a condition for the possibility of natural science because of the latter’s reliance upon experiments. If human freedom is an illusion, then results of experiments (whose aims, methods, and conditions are chosen) are illusions, and thus the advance of the natural sciences as corroborated by experiments is an illusion.