Combining Philosophers

All the ideas for Rescher,N/Oppenheim,P, Jan Lukasiewicz and Augustus De Morgan

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5 ideas

4. Formal Logic / E. Nonclassical Logics / 3. Many-Valued Logic

8942	Lukasiewicz's L3 logic has three truth-values, T, F and I (for 'indeterminate') [Lukasiewicz, by Fisher]

5. Theory of Logic / E. Structures of Logic / 6. Relations in Logic

17744

De Morgan started the study of relations and their properties [De Morgan, by Walicki]

13501

De Morgan found inferences involving relations, which eluded Aristotle's syllogistic [De Morgan, by Hart,WD]

5. Theory of Logic / G. Quantification / 2. Domain of Quantification

17743

De Morgan introduced a 'universe of discourse', to replace Boole's universe of 'all things' [De Morgan, by Walicki]

9. Objects / C. Structure of Objects / 8. Parts of Objects / c. Wholes from parts

12887

A whole must have one characteristic, an internal relation, and a structure [Rescher/Oppenheim]