An informal fallacy; when a statement is asserted that is theoretically or practically impossible to test. An unstable hypothesis is one that science and logic cannot address, and one from which no empiric information can arise. These are often fun for thought-experiments however. And, when treated appropriately, and lead to testable theories, and even massive scientific breakthroughs. (See; Einsteins ‘riding on/chasing a beam of light‘ thought experiment)
Example: 1) I propose X. 2) X cannot be seen using any kind of equipment.
Real World Example:
A common example is Carl Sagan’s, invisible, heat-less, weightless dragon that lives in his garage. The dragon is/was completely invisible to everyone but him, its fire didn’t burn, ect. (More here). The dragon is test-proof and therefore perfectly embodies this fallacy.
Indicator: This is a fallacy you just have to watch out for. It’s quite glaring once seen, and hard to miss most of the time. Few of those who propose theories that qualify as unfalsifiable will openly admit that it is such. But when all proposed tests are explained as in some way ‘invalid’, that’s a clear indicator. In this way, this fallacy is similar to the Special Pleading fallacy.
Next week: Misleading Vividness
Last week: Weak Analogy