Principles of Logic |
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Common terms and phrases
abstract accident affirmed Analogy Analytic proposition animal antecedent applied argument Aristotle assert attribute belongs Boethius categorical proposition Categories causal cause characteristics chiliagons conceived concept conceptual order conclusion connexion connotation considered constitute contradictory Contrapositive Conversion copula definition denied denote determined differentia disjunctive distinction division effect employed Enthymeme entity existence experience explained expressed fact fallacy false genus Hence hypothesis hypothetical hypothetical syllogism Ignoratio Elenchi immediate inference individual Induction instance intellect judgment knowledge laws of thought Logic logicians major premiss meaning mental merely Metaphysics method middle term Mill mind mortal nature negative object observed Obversion particular philosophy polysyllogism possess predicate principle question quod real order reason regard relation represented rules Scholastic Scholasticism sense signify singular Socrates species subject and predicate substance syllogism theory thing Thomas thought tion triangle true truth universal proposition whole word τὸ
Popular passages
Page 273 - The only proof capable of being given that an object is visible, is that people actually see it. The only proof that a sound is audible, is that people hear it: and so of the other sources of our experience. In like manner, I apprehend, the sole evidence it is possible to produce that anything is desirable, is that people do actually desire it.
Page 418 - Matters of fact, which are the second objects of human reason, are not ascertained in the same manner; nor is our evidence of their truth, however great, of a like nature with the foregoing. The contrary of every matter of fact is still possible; because it can never imply a contradiction, and is conceived by the mind with the same facility and distinctness, as if ever so conformable to reality.
Page 19 - A NAME is a word taken at pleasure to serve for a mark, which may raise in our mind a thought like to some thought we had before, and which being pronounced to others, may be to them a sign of what thought the speaker had, or had not before in his mind.
Page 196 - All men are mortal Socrates is a man therefore Socrates is mortal; it is unanswerably urged by the adversaries of the syllogistic theory, that the proposition, Socrates is mortal...
Page 404 - God himself who has created it, and without enducing them from any other source than from certain germs of truths naturally existing in our minds. In the second place, I examined what were the first and most ordinary effects that could be deduced from these causes; and it...
Page 322 - If an instance in which the phenomenon under investigation occurs, and an instance in which it does not occur, have every circumstance in common save one, that one occurring only in the former; the circumstance in which alone the two instances differ is the effect, or the cause, or an indispensable part of the cause, of the phenomenon.
Page 241 - The Law of Causation, the recognition of which is the main pillar of inductive science, is but the familiar truth that invariability of succession is found by observation to obtain between every fact in nature and some other fact which has preceded It...
Page 153 - The former of these propositions is not a definition at all: the latter is a mere nominal definition, or explanation of the use and application of a term. The first is susceptible of truth or falsehood, and may therefore be made the foundation of a train of reasoning.
Page 241 - If this be actually done, the principle which we are now considering, that of the uniformity of the course of nature, will appear as the ultimate major premise of all inductions...
Page 347 - ... the squares of the periodic times are as the cubes of the distances from the common centre, the centripetal forces will be inversely as the squares of the distances.