 | Augustus De Morgan - 1847 - 376 pàgines
...(A),E,O From (O) ... A, (E), I Thefe may be thus fummed up : The affirmation of a univerfal propofition, and the denial of a particular one, enable us to affirm...or deny all the other three ; but the denial of a univerfal propofition, and the affirmation of a particular one, leave us unable to affirm or deny two... | |
 | Alfred Milnes - 1880 - 140 pàgines
...the other. And the results of the formulae may, as a whole, be summed up in the following rule : — The affirmation of a universal proposition, and the...leave us unable to affirm or deny two of the others. " It is a rule of practical Logic that a contradictory should always in disputations be used in preference... | |
 | James Welton - 1917 - 380 pàgines
...hold. I and O : subcontrary relation. Both may be true ; both cannot be false. Or, more generally : " The affirmation of a universal proposition, and the...leave us unable to affirm or deny two of the others." * (vii) OPPOSITION OF SINGULAR PROPOSITIONS. — -The relations we have considered hold between propositions... | |
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These may be thus summed up : The affirmation of a universal proposition, and the denial of a particular one, enable us to affirm or deny all the other three ; but the denial of a universal proposition, and the affirmation of a particular one, leave us... 