Abduction or the Logic of Surprise

Abstract

In the obituary of Jon Barwise, one of the greatest logicians of the secondhalf of the twentieth century, Jon Dorbolo recalls how Barwise usedto remark that ‘logic is not playing games with symbols,’ but it ‘is thescience of valid reasoning’ (Dorbolo 2000: 179). Everyone who hastaught logic at any level has noticed how di‰cult is — contrary to whatmight, in principle, be expected — to combine pure thought with real lifein their pedagogy, in order to help the students to discover that what istaught in the classroom has some relation with their ordinary way ofthinking.The causes of this phenomenon are very complex, and are not reducibleto a fear of psychologism or to the mathematization of modern logic sinceFrege. As is well known, the humanists of the fifteenth century were al-ready very critical of the later medieval logicians, accusing them of hav-ing lost contact with the real problems in the middle of the obscure scho-lastic debates. For instance, according to Juan Luis Vives it is necessary‘to transform logic into a useful and practical tool, because the disciplinesthat deal with language are necessarily linked with vital and concrete ex-perience’ (Mun˜oz Delgado 1986: 119; Ashworth 1982; Cerezo 1996). Infact, much of the great interest in philosophy of language in the secondhalf of the twentieth century has had a direct relation with this questionof providing context for logic. Nevertheless, it is not enough to bring lifeback to logic by paying more attention to language. It will be also neces-sary to pay attention to the real processes through which human beings,professors of logic or lay people, acquire new ideas and discover newknowledge.