Cribs in the Voynich MS

[Mark Knowles]

What I find tricky about using cribs is the accumulation of uncertainties. In this case:

Are they a random number of stars (like in the example I linked above) or is the number meaningful?
If the number is relevant, are they Pleiades or a different group of seven stars? Examples are the planets and certain other constellations (Some Ursa? It's been a while.)
If they are Pleiades, are we looking at the "scientific" name or a vernacular version like "sisters"?
If scientific, then Greek or an Arabic version?
If vernacular, then which language?
If any of the above, then which spelling?

Now imagine a theorist looking for confirmation for his system. He could use any of the steps above to fashion something out if this crib that is to his liking.

You are right. It would be and is easy to use a suggested incorrect crib to come up with a completely erroneous theory. As Nick Pelling points our this is a common problem with many Voynich theories in the past and present. However this doesn’t detract from the immense value of an accurate crib. Cribs are the bread and butter that have served so many decipherers throughout time and consistently have been used to decipher unknown languages and break ciphers. So we shouldn't discount them. However we need to exercise extreme caution when using them for precisely the reasons that you suggest above. When used correctly they are priceless. When used incorrectly they are worse than useless.