Full Idea
In fuzzy logic objects have properties to a greater or lesser degree, and truth values are given as fractions or decimals, ranging from 0 to 1. Not-p is defined as 1-p, and other formula are defined in terms of maxima and minima for sets.
Gist of Idea
Fuzzy logic has many truth values, ranging in fractions from 0 to 1
Source
Jennifer Fisher (On the Philosophy of Logic [2008], 07.II)
Book Reference
Fisher,Jennifer: 'On the Philosophy of Logic' [Thomson Wadsworth 2008], p.100
A Reaction
The question seems to be whether this is actually logic, or a recasting of probability theory. Susan Haack attacks it. If logic is the study of how truth is preserved as we move between propositions, then 0 and 1 need a special status.