Logic, Deductive and Inductive

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1898 edition. Excerpt: ...examination of as many instances as can be found, relying for the rest upon the mere undefinable principle of the Uniformity of Nature, since we are not able to connect them with any of its definite modes enumerated in chap. xiv. 1. To this subject we shall return in chap, xix, after treating of Methodical ... Read More

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1898 edition. Excerpt: ...examination of as many instances as can be found, relying for the rest upon the mere undefinable principle of the Uniformity of Nature, since we are not able to connect them with any of its definite modes enumerated in chap. xiv. 1. To this subject we shall return in chap, xix, after treating of Methodical Induction, or the means of determining that a connection of events is of the nature of Cause and Effect, because the relation can be shown to have the marks of causation, or some of them. 5. Observations and Experiments are the material grounds of induction. An experiment is an observation made under prepared, and therefore known, conditions; and, when obtainable, it is much to be preferred. Simple observation shows that the burning of the fire depends, for one thing, on the supply of air; but it cannot show us that it depends on oxygen. To prove this we must make experiments; as by obtaining pure oxygen and pure nitrogen (which, mixed in the proportion of one to four, form the air) in separate vessels, and then plunging a burning taper into the oxygen--when it will blaze fiercely, and again plunging it into the nitrogen--when it will be extinguished. This shows that the greater part of the air does nothing to keep the fire alight, except by diminishing its intensity and so making it last longer. Experiments, now, are more perfect the more carefully they are prepared, and the more completely the conditions are known under which the given phenomenon is to be observed. Plainly, however, experiments are only possible when some knowledge has already been gained by observation, or else the preparation which they require would be impossible. Observation, then, was the first material ground of induction, and in some sciences it remains... Read Less