A contribution to the psychology of logic : considered from a physiological standpoint / by Augustus D. Waller.

  • Augustus Desiré Waller
Date:
1912
Catalogue details

Licence: Public Domain Mark

Credit: A contribution to the psychology of logic : considered from a physiological standpoint / by Augustus D. Waller. Source: Wellcome Collection.

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    naturally to such limited phenomenal fields as can be mentally embraced through our sensory organs.] The sixteen co-extensions given in the Table above are logically and psychologically redundant, by reason of the limitation of scope introduced by the quantified predicate. S Whereas the classificatory statement S is P or — cannot be simply transposed to give the statement P is S, a quantified statement S is co-extensive with P or S = P can be so transposed to give the statement P is £ or P = S. Again if S = aP necessarily aP = S where logically considered aP is the subject and S the predicate of the verbalised proposition. And now we realise that this new subject aP, in spite of its formal limitation, is psychologically an entire and unlimited subject. A verbal example may help to make this point clear :— An original] All slaves proposition J S Simply ] Certain men transposed / aP are co-extensive with are co-extensive with certain men aP all slaves S In the original proposition the subject S is unlimited or total, and the predicate aP is quantified as being equal to S. In the transposed proposition the new subject aP, although formally a particular or partial expression, is psychologically a subject taken in its totality, i. e. the entire group of men quantified in relation to all slaves. Or again, taking a co-extension with both terms particular :— This Space aS is co-extensive with that Pond bP