It is perhaps a poor name? If it relies on probability, then I am willing to bet there's a completely logically foundation for fuzzy logic, which in turn relies on the axiomatic set up on probability I already mentioned.

There is only one way in which I came anywhere close to fuzzy logic of which I am aware. A prof had handed off to me something he had not been able to completely solve. He thought it would only get to a certain point and then would have to go off into something probabilistic. (We knew we could not determine the number of some things completely and why. But, I was able to show him that through a change in perspective we could determine it concretely with only one thing unknown, eliminating the need for probabilistic solutions.)

Errr, completely logical.

Course run.