Formal Logic: Or, The Calculus of Inference, Necessary and ProbableTaylor and Walton, 1847 - 336 pages |
Autres éditions - Tout afficher
Formal Logic: Or, The Calculus of Inference, Necessary and Probable Augustus De Morgan Affichage du livre entier - 1847 |
Formal Logic: Or, The Calculus of Inference, Necessary and Probable Augustus De Morgan Affichage du livre entier - 1847 |
Formal Logic: Or, The Calculus of Inference, Necessary and Probable Augustus De Morgan Affichage du livre entier - 1847 |
Expressions et termes fréquents
abſolute affert affirmative alſo anſwer argument aſſertion aſſumed ball becauſe cafe caſe claſs complex conclufion confideration confidered conſequence conſiſts contained contrary courſe deſcribed deſcription diftinguiſhed elſe eſtabliſhed exiſt expreſſed fallacy falſe fame firſt fome forms fyllo fyllogifm genus give Hamilton idea ignoratio elenchi impoſſible inference inſtances itſelf juſt laſt leſs logic meaning middle term mode moſt muſt neceſſarily neceſſary negative number of Xs object obſerve particular perſon poſitive poſſible predicate premiſes preſent probability proceſs propoſe propoſition quantity queſtion reaſon repreſent reſpect reſult rule ſaid ſame ſay ſcience ſecond ſee ſeems ſeen ſenſe ſeparate ſet ſeveral ſhall ſhould ſhow ſimple Sir William Hamilton ſome ſomething ſometimes ſpeak ſpecies ſpoken ſpurious ſtand ſtate ſtatement ſtill ſtrengthened ſtudy ſubidentical ſubject ſubſtitution ſuch ſuggeſt ſuppoſe ſuppoſition ſyllogiſm ſymbol ſyſtem teftimony theſe thing thoſe tion true truth univerſal uſe uſual witneſs word Xs are Ys
Fréquemment cités
Page 266 - ... fcenes, he feems to produce without labour, what no labour can improve* In tragedy he is always ftruggling after fome occafion to be...
Page 205 - Organum. It is indeed an elaborate and correct analysis. But it is an analysis of that which we are all doing from morning to night, and which we continue to do even in our dreams.
Page 160 - By degree of probability we really mean, or ought to mean, degree of belief. It is true that we may, if we like, divide probability into ideal and objective, and that we must do so, in order to represent common language.
Page 161 - An omniscient being would never employ probable inferences, since every proposition would be known to be certainly true or certainly false. Beings lacking omniscience must rely on probabilities, since their knowledge is incomplete, and probability measures their ignorance. When we feel altogether...
Page 64 - A is greater than B, B is greater than C, therefore A is greater than C.
Page 15 - I would not dissuade a student from metaphysical inquiry ; on the contrary I would rather promote the desire of entering on such subjects ; but I would warn him, when he tries to look down his own throat with a candle in his hand, to take care that he does not set his own head on fire...
Page 111 - B, or if C is D, E is F ; But either A is B, or C is D ; /. E is F.
Page 225 - there is no such thing as a classification of the ways in which men may arrive at an error: it is much to be doubted whether there ever can be."* Surely, there can be no conclusive and comprehensive classification.
Page 316 - A it affirms of this, tJvese, all — Whilst E denies of any : I, it affirms, whilst 0 denies, Of some (or few or many). Thus A affirms, as E denies, And definitely either : Thus I affirms, as O denies, And definitely neither. A half, left semi-definite, Is worthy of its score ; U, then, affirms, as Y denies, This, neither less nor more.
Page 24 - ... Whately, understands by a Real Definition one which contains less than the Nominal Definition, provided only that what it contains is sufficient for distinction. "By real definition I mean such an explanation of the word, be it the whole of the meaning or only part, as will be sufficient to separate the things contained under that word from all others. Thus the following, I believe, is a complete definition of an elephant: An animal which naturally drinks by drawing the water into its nose, and...