119.

119.

Mexico: Universidad Nacional Autonoma de Mexico, 1989, 323 pp.

120.

120.

I am very thankful to Raul Orayen for his comments on a previous version of this paper and to J.J.C. Smart for his kind help in making its style less unEnglish.

45. 3_1.

The notion of fuzzy set was first endowed with a formal treatment by Lofti Zadeh in 1965. A huge literatures has at this stage been published developing its theory and applications in an impressive variety of fields.

46. 3_2.

The proof that the thus weakened truth theory still contains contradictions (in virtue or the previously attained result that, for some &leftcorner;p&rightcorner;, ∴~T#p<=>p) involves abduction rules for the noncontraposible conditional `⇒', namely p⇒~p ∴ ~p and ~p⇒p ∴ p -- although the point is not made quite clear in the text. The whole treatment is somehow marred by the fact that `⇒' is not provided with an English reading; and, once contraposition has been junked for it, I surmise that not everybody will accept the abduction rules. If you relinquish the naive simplicity underlying the original T schema -- namely that &leftcorner;p&rightcorner;'s truth is just the fact that p (with the strongest biimplication thus linking the fact that p with &leftcorner;p&rightcorner; being true)--, I guess some contradiction-averting manoeuvres become less implausible: e.g. refusing to accept either of the abduction rules for conditional `⇒'.

47. 3_3.

Thanks are due to Graham Priest and Francisco J.D. Ausín for helpful comments on an early draft of this review, which was written in Canberra during my stay as Visiting Scholar at the Research School of Social Sciences of the Australian National University (1992-1993). The delay in publishing the review is entirely my own fault -- the only excuse being that I have long harboured doubts on whether my objections to Priest's approach were as cogent as I wanted them to be. That is now for the reader to judge.