Single Idea 17895

[catalogued under 5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / d. and]

Full Idea

In 'Caesar is dead, and Brutus is alive' ...there are here two distinct assertions; and we might as well call a street a complex house, as these two propositions a complex proposition.

Gist of Idea

Combining two distinct assertions does not necessarily lead to a single 'complex proposition'

Source

John Stuart Mill (System of Logic [1843], 1.04.3)

Book Reference

Mill,John Stuart: 'System of Logic (9th ed, 2 vols)' [Longmans, Green etc 1875], p.90


A Reaction

Arthur Prior, in his article on 'tonk', cites this to claim that the mere account of the and-introduction rule does not guarantee the existence of any conjunctive proposition that can result from it. Mill says you are adding a third proposition.