I think we know that sound change is at least partly regular, because we have a mass of evidence showing regular sound correspondences. The reason we assume that sound change is invariably regular is because it lets us make predictions and falsifiable hypotheses.
Utter nonsense! You’re using the correct word when you call it an “hypothesis” or “assumption”— rather than the “inviolable law” linguists have been pawning it off as. But you obviously don’t know or want to know what falsifiability is because I just falsified the hypothesis that Gk, L, and Skt
*p and
*d can't possible correspond to Gc
*p and
*d. So maybe you can tell me how I can falsify that hypothesis any better ? I’d really like to hear that one.
In other words, it's a useful assumption.
Sure. So was the assumption that the Sun revolved around the earth in that it allowed Ptolemaic astronomers to develop a system of concentric circles that predicted some things about planetary motion. The problem was that the predictions didn’t match the observations, just as the prediction that Gk, L, and Skt
*p and
*d invariably correspond to Gc
*f and
*t don’t match the observations. In both cases the hypotheses were wrong.
So Ptolemaic astronomers egregiously violated Occham’s Razor — I’m assuming you know what that is — by adding more and more hypotheses to their system in an effort to make the system fit the observations, or just ignoring the discrepancies. By the same token, linguists kept hypothesizing the existence of unattested words and PIE roots to make the evidence fit their theories, or they just ignored the discrepancies, like the ones I just showed you and hundreds of others.
Then, when Copernicus theorized that the earth revolved around the sun, and Galileo proved it telescopically by observing Venus’s phases, these astronomers just ignored them, too. And the Catholic Church, whose belief system hinged on geocentrism to an extraordinary extent, maintained a geocentric position for centuries after that pudding was proven.
It is for the very same reasons that historical linguistics is, at worst, a pseudo-science, and at best, a proto-science. But if the history of science repeats itself, as it surely will, it could be some time before linguists are ready to accept the fact that their allegedly precise science is nothing but a house of cards.
If we assume that sound change isn't invariably regular, then we can't predict how the forms of words will differ across languages, and every hypothesis we make is as valid as any other. I have no interest in that sort of theory, it's not useful or interesting. You've simply asserted that some words are related, without offering an explanation of the various historical processes that led to the different forms. Why do some of the Germanic words begin with p and some with f.
I’m sorry. But my patience is at an end!
OP
Lignify