Do we need “fuzzy logic”?

✍ Scribed by Susan Haack

• Publisher: Elsevier Science
• Year: 1979
• Weight: 573 KB
• Volume: 11
• Category: Article
• ISSN: 0020-7373
• DOI: 10.1016/s0020-7373(79)80036-x

✦ Synopsis

This paper gives a critical appraisal of "fuzzy logic" from the viewpoint of a logician and concludes that no acceptable case has been made for the need for it.

[Its] shortcomings.., are rooted in a certain softness and instability of [ordinary] language, which nevertheless is necessary for its versatility and potential for development. In this respect ordinary language can be compared to the hand, which despite its adaptability to the most diverse tasks is still inadequate. We build for ourselves artificial hands, tools for particular purposes, 9 which work with more accuracy than the hand can provide. And how is this accuracy possible? Through the very stiffness and inflexibility of parts the lack of which makes the hand so dextrous. Word-language is inadequate in a similar way. We need a system of symbols from which every ambiguity is banned, which has a strict logical form from which the content cannot escape.

(Gottlob Frege, On the Scientific Justification of A Conceptual Notation, p. 86) Formal logic is... incapacitated by its self-imposed limitation from dealing with the problems of actual thinking and from rationally interpreting the conception of truth implied in such thinking .... We need, in short, a second [non-formal] Logic which will be applicable to life and relevant to actual thought.