Logic: Designed as an Introduction to the Study of ReasoningW. Allen, 1864 - 209 σελίδες |
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Συχνά εμφανιζόμενοι όροι και φράσεις
admitted affirmed or denied ambiguity animal antecedent applied argu argument ascertained assertion assumed belongs Cæsar called categorical categorical propositions categorical syllogism Christian circle clusion conclusion conditional proposition conditional syllogism connexion consequent considered conversion definition denoted deserved death disjunctive disjunctive proposition distinct distributed drawn Duke of Wellington employed Enthymeme error evidence example expressed facts fallacy false Figure founded genus gism given happy Hence HYPOTHETICAL SYLLOGISMS illicit process Induction Inductive philosophy inference instance Julius Cæsar kind knowledge Logician major premise means men are mortal ment merely method middle term mind minor term miserable Moods mortal nature necessary negative object observation particular person petitio principii philosophy predicate prejudices principles process of reasoning proof proved province of Logic quadruped reasoning process reduced regular syllogism respecting rules sense shew sion sophism Sophist Sorites species supposition syllogistic takes place testimony things tion triangle true truth tyrants validity whole words
Δημοφιλή αποσπάσματα
Σελίδα 37 - A circle is a plane figure contained by one line, which is called the circumference, and is such that all straight lines drawn from a certain point within the figure to the circumference, are equal to one another.
Σελίδα 147 - It must be granted that in every syllogism, considered as an argument to prove the conclusion, there is a petitio principii. When we say, All men are mortal ; Socrates is a man ; Therefore, Socrates is mortal...
Σελίδα 141 - Our object, therefore, will be to attempt a correct analysis of the intellectual process called Reasoning or Inference, and of such other mental operations as are intended to facilitate this : as well as, on the foundation of this analysis, and pari passu with it, to bring together or frame a set of rules or canons for testing the sufficiency of any given evidence to prove any given proposition.
Σελίδα 108 - Achilles run ten times as fast as the tortoise, yet if the tortoise has the start, Achilles will never overtake him. For suppose them to be at first separated by an interval of a thousand feet: when Achilles has run these thousand feet, the tortoise will have got on a hundred; when Achilles has run those hundred, the tortoise will have run ten, and so on for ever: therefore Achilles may run for ever without overtaking the tortoise. Now, the *
Σελίδα 143 - Not only may we reason from particulars to particulars without passing through generals, but we perpetually do so reason. All our earliest inferences are of this nature. From the first dawn of intelligence we draw inferences, but years elapse before we learn the use of general language. The child, who, having burned his fingers, avoids to thrust them again into the fire, has reasoned or inferred, though he has never thought of the general maxim, Fire burns.
Σελίδα 143 - He knows from memory that he has been burnt, and on this evidence believes, when he sees a candle, that if he puts his finger into the flame of it, he will be burnt again. He believes this in every case which happens to arise; but without looking, in each instance, beyond the present case. He is not generalizing; he is inferring a particular from particulars. In the same way, also, brutes reason.
Σελίδα 154 - All inference is from particulars to particulars: General propositions are merely registers of such inferences already made, and short formulae for making more: The major premiss of a syllogism, consequently, is a formula of this description: and the conclusion is not an inference drawn from the formula, but an inference drawn according to the formula: the real logical antecedent, or...
Σελίδα 140 - Logic, then, is the science of the operations of the understanding which are subservient to the estimation of evidence: both the process itself of proceeding from known truths to unknown, and all other intellectual operations in so far as auxiliary to this.
Σελίδα 144 - In so far as belief professes to be founded on proof, the office of logic is to supply a test for ascertaining whether or not the belief is well grounded.