To anyone studying pseudoscience and weird beliefs, the idea of certainty creep is an important one. I thought I had invented this term but when I looked it up on Google, I found that others have coined it before me. The idea is very simple. You start with a theory which is tentative. You claim, for example, that jasm comes from the Irish teas ioma, which means (according to you) excessive heat or ‘figuratively semen’. Then it enters cyberspace and people start to copy it. Do they copy the whole thing? No, they copy the most satisfying, wow-factor bit, so teas ioma becomes a phrase meaning semen. Then someone else copies it and it becomes ‘the Irish for semen’. And so on until all doubt and negativity have been removed and a silly made-up phrase is passed off as genuine Irish.
Related to this is the useful concept of accuracy slip. This is basically what happens in Chinese whispers. Gradually, the claim gets further and further away from what was originally suggested. Of course, in a sense, certainty creep is a sub-category of accuracy slip. In some cases, the transformation of material will be fairly random, but in other cases it will be motivated by a desire to make the story ‘better’ – i.e. to make the facts fit the myth, and that is certainty creep.
Incidentally, in the example above, teas does mean heat. Ioma is a variant of iomaí, which means excessive but cannot be used the way Cassidy uses it, so teas ioma is just a meaningless piece of nonsense. Even if it did mean ‘excessive heat’, is this really going to mean the same as semen?
Hardly! This is yet another example of Daniel Cassidy’s bizarre fantasy world.