Aristotle, Volume 31; Volume 187

Front Cover
J. Murray, 1880 - History - 681 pages
Aristotle's emphasis on the syllogism leads him to conceive of knowledge as hierarchically structured, a claim that he fleshes out in the Posterior Analytics. To have knowledge of a fact, it is not enough simply to be able to repeat the fact. We must also be able to give the reasons why that fact is true, a process that Aristotle calls demonstration. Demonstration is essentially a matter of showing that the fact in question is the conclusion to a valid syllogism. If some truths are premises that can be used to prove other truths, those first truths are logically prior to the truths that follow from them. Ultimately, there must be one or several "first principles," from which all other truths follow and which do not themselves follow from anything.

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Page 156 - Euclid's, and show by construction that its truth was known to us ; to demonstrate, for example, that the angles at the base of an isosceles triangle are equal...
Page 211 - General laws may be laid down respecting the tides, predictions may be founded on those laws, and the result will in the main, though often not with complete accuracy, correspond to the predictions. And this is what is or ought to be meant by those who speak of sciences which are not exact sciences. Astronomy was once a science, without being an exact science. It could not become exact until not only the general course of the planetary motions, but the perturbations also, were accounted for, and...
Page 476 - But another man, who never took the pains to observe the demonstration, hearing a mathematician, a man of credit, affirm the three angles of a triangle to be equal to two right ones, assents to it, ie receives it for true.
Page 211 - ... phenomenon in general, but of all the variations and modifications which it admits of. But inasmuch as other, perhaps many other causes, separately insignificant in their effects, co-operate or conflict in many or in all cases with those greater causes; the effect, accordingly, presents more or less of aberration from what would be produced by the greater causes alone. Now if these minor causes are not so constantly accessible, or not accessible at all, to accurate observation ; the principal...
Page 658 - But whether we choose life for the sake of pleasure or pleasure for the sake of life is a question we may dismiss for the present.
Page 211 - The science of human nature is of this description. It falls far short of the standard of exactness now realized in Astronomy; but there is no reason that it should not be as much a science as Tidology is, or as Astronomy was when its calculations had only mastered the main phenomena, but not the perturbations.
Page 90 - Such an analysis, however superficially conducted, would have shown the enumeration to be both redundant and defective. Some objects are omitted, and others repeated several times under different heads.
Page 460 - The soul is the cause and principle of a living body:* by which is meant, not an independent and pre-existent something that brings the body into existence but, an immanent or indwelling influence which sustains the unity and guides the functions of the organism.
Page 211 - Any facts are fitted, in themselves, to be a subject of science, which follow one another according to constant laws ; although those laws may not have been discovered, nor even be discoverable by our existing resources. Take, for instance, the most familiar class of meteorological phenomena, those of rain and sunshine. Scientific inquiry has not yet succeeded in ascertaining the order of antecedence and consequence among these phenomena, so as to be able, at least in our regions of the earth, to...
Page 461 - We proceed onward in the same direction, taking in additional faculties — the Movent, Appetitive, Phantastic (Imaginative) Noetic (Intelligent) soul, and thus diminishing the total of individuals denoted. But each higher variety of soul continues to possess all the faculties of the lower. Thus the Sentient soul cannot exist without comprehending all the faculties of the Nutritive, though the Nutritive exists (in plants) without any admixture of the Sentient.

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