A Treatise on Logic: Or, The Laws of Pure Thought; Comprising Both the Aristotelic and Hamiltonian Analyses of Logical Forms, and Some Chapters of Applied LogicSever and Francis, 1865 - 450 páginas |
Términos y frases comunes
absolutely actually affirm the Consequent Affirmative already animal antecedent applied Aristotle assertion attributes Axiom called Cause class of things classification conceived Concept Conclusion connoted Consequent considered contained Contradictory Contraposition Conversion Copula Definition Demonstrative denote deny determined Disjunctive Disjunctive Syllogism distinct enounced Enthymeme equal event evidence Excluded exists explicated expressed Extension fact faculty Fallacy false Figure former Genus gism Hamilton Hence Immediate Inference individual Induction Inductive Reasoning infinite instance Intension Intuition knowledge language Laws of Thought Logic logicians Major Premise Marks Matter meaning ment mental merely Middle Term mind mode Modus tollens Moods nature necessary Negative not-X notion objects observed particular peculiar perception Predicate principle properly Proposition proved Pure Thought qualities Quantity rational reasoning reduced relation respect Rule sion Sir William Hamilton sophism Species Subalternation Subject sublating Sumption Syllogism tion tive true truth Universal valid whole words
Pasajes populares
Página 423 - The strength of a chain is the strength of its weakest link, the engineers tell us," said Longworth, " and it is the same with evidence.
Página 392 - It consists in ascribing the character of general truths to all propositions which are true in every instance that we happen to know of.
Página 400 - Cause is the sum total of the Conditions, positive and negative, taken together ; the whole of the contingencies of every description, which, being realized, the consequent invariably follows.
Página 24 - And a little attention will discover that it is not necessary (even in the strictest reasonings) that significant names which stand for ideas should, every time they are used, excite in the understanding the ideas they are made to stand for : in reading and discoursing, names being for the most part used as letters are in Algebra...
Página 297 - Englishmen or not-Englishmen,' to the exclusion of the third possibility of a mixed force, so it is false to say, ' Every body must move in the place where it is, or in the place where it is not,' to the exclusion of the third possibility of moving partly in the one and partly in the other.
Página 337 - ... printing, gunpowder, and the magnet. For these three have changed the whole face and state of things throughout the world; the first in literature, the second in warfare, the third in navigation; whence have followed innumerable changes; insomuch that no empire, no sect, no star seems to have exerted greater power and influence in human affairs than these mechanical discoveries.
Página 175 - In as far as two notions (notions proper or individuals), either both agree, or one agreeing, the other does not, with a common third notion ; in so far, these notions do or do not agree with each other.
Página 392 - To an inhabitant of Central Africa, fifty years ago, no fact probably appeared to rest on more uniform experience than this, that all human beings are black. To Europeans, not many years ago, the proposition, All swans are white, appeared an equally unequivocal instance of uniformity in the course of nature. Further experience has proved to both that they were mistaken; but they had to wait fifty centuries for this experience.
Página 290 - Rules may be violated in appearance, when they are not so in reality. For instance: — . No one is rich who has not enough; No miser has enough ; Therefore no miser is rich. Here, both Premises are seemingly negative ; but they are not really so, for the negation of having enough is a part of the Predicate, and therefore does not affect the Quality of the Judgment, which depends on the Copula. Instead of not having enouffh, substitute the equivalent phrase, wanting more, and the seeming incorrectness...
Página 391 - On the contrary, everybody mentions it as something extraordinary, if the course of nature is constant, and resembles itself, in these particulars. To look for constancy where constancy is not to be expected, as, for instance, that a day which has once brought good fortune will always be a fortunate day, is justly accounted superstition. The course of nature, in truth, is not only uniform, it is also infinitely capricious. Some phenomena are always seen to recur in the very same combinations in which...