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Ways of understanding hugh Maccoll's concept of symbolic existence

1998; University of Oslo; Volume: 3; Linguagem: Inglês

0806-6213

Shahid Rahman,

Logic, Reasoning, and Knowledge

Hugh MacColl (1837-1909) proposed, in several papers, a non-standard way of understanding the ontology underlying what we today call quantified propositions. His ideas, mixed with reflections about the use of arbitrary objects, were not greatly successful and were ruthlessly criticised by Bertrand Russell especially. The aim of this paper is to show that a thorough reading of MacColl's general understanding of symbolic existence, a concept which is connected with his view of traditional hypotheticals, elucidates his proposals on the role of ontology in logics. The interpretation of MacColl's concept of symbolic existence put forward in this paper and embedded in a dialogical system of free logic can be expressed in a nutshell: in any argumentation, it sometimes makes sense to restrict the use and introduction of singular terms in the context of quantification to a formal use of those terms. That is, the Proponent is allowed to use a constant iff this constant has been explicitly conceded by the Opponent. The paper also offers a second way of reconstructing MacColl's ideas on contradictory objects by means of combining the concept of formal use of constants in free logics and that of the formal use of elementary negations in paraconsistent logics.