Semiotics 1980 pp 513-522

The Application of the Peircean Semiotic to Logic

• Bruce E. R. Thompson

Abstract

The loose and sloppy explanation of the difference between Induction and Deduction,--the explanation which is sometimes still taught to freshman English students--is that Deduction moves from general to specific, while Induction moves from specific to general. This account has been sufficiently discredited that I do not need to dwell on the arguments here. The more often accepted explanation is that in Deduction the conclusion follows from the premises with certainty while in Induction the conclusion follows only with some degree of probability. Of course we cannot claim that the conclusion of a Deductive argument really is certain, since the conclusion can be no better than the premises upon which it rests. What we mean is that the conclusion of a Deductive argument would be certain if we could first lay to rest any conceivable doubt concerning the truth of the premises. Any argument in which the premises fail to provide this kind of support must fall into the category of Induction. The unfortunate consequence of this account, however, is that invalid Deductions cannot be called Deductions at all, but are rather Inductions, since the conclusion does not follow from the premises with absolute certainty. This shows the need for a way of distinguishing kinds of reasoning which will provide an independent criterion for distinguishing good from bad examples of each kind of reasoning.

Keywords

Unfortunate Consequence Deductive Argument Connotative Meaning Subjunctive Mood Logical Justification
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Footnotes

1. 1.
MS L 77, p. 52. (See Richard S. Robin, “Annotated Catalogue of the Papers of Charles S. Peirce,” University of Mass. Press, 1967.)Google Scholar
2. 2.
Charles S. Hardwick, ed.45emiotic and Significs: The Correspondence between Charles S. “Peirce and Victoria Lady Welby,” Indiana University Press, Bloomington, 1977, p. 85.Google Scholar
3. 3.
309 (Decimal numbers refer to volume and paragraph of the“Collected Papers of Charles S. Peirce,” Harvard University Press, Cambridge, 1932–34.)Google Scholar
4. 16.
Semiotics and Significs op. cit., p. 111.Google Scholar