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chologist does the same thing mentally. . . . In contemplating mind, he may think of its capacity of feeling without thinking of its power of activity, or the faculty of memory apart from any or all of the other faculties with which it is allied. ABSTRACTION (LOGICAL),

66 As we have described it,” says Mr. Thomson (Outline of the Laws of Thought p. 107), “would include three separate acts ; first, an act of comparison, which brings several intuitions together; next, one of reflection, which seeks for some marks which they all possess, and by which they may be combined into one group ; and last, one of generalization, which forms the new general notion or conception. Kant, however, confines the name of abstraction to the last of the three ; others apply it to the second. It is not of much consequence whether we enlarge or narrow the meaning of the word, so long as we see the various steps in the process.

The word means a drawing away of the common marks from all the distinctive marks which the single objects have.” Mr. J. S. Mill uses the term abstract as opposed to concrete. By an abstract name he means the name of an attribute—by a concrete name the name of an object.



231. 1. From Fleming's Vocabulary of Philosophy, ed. 1867.

Generalization is the act of comprehending, under a common name, several objects agreeing in some point which we abstract from each of them, and which that common name serves to indicate."

When we are contemplating several individuals which resemble each other in some part of their nature, we can (by attending to that part alone, and not to those points wherein they differ) assign them one common name, which will express or stand for them merely as far as they all agree; and which, of course, will be applicable to all or any of them (which process is called generalization); and each of these names is called a common term, from its belonging to them all alike; or a predicable, because it may be predicated affirmatively of them or any of them.

Generalization is of two kinds-classification and generalization properly so called.

When we observe facts accompanied by diverse circumstances, and reduce these circum


stances to such as are essential and common, we obtain a law.

When we observe individual objects and arrange them according to their common charac. ters, we obtain a class. When the characters selected are such as belong essentially to the nature of the objects, the class corresponds with the law. When the character selected is not natural the classification is artificial. If we were to class animals into white and red, we would have a classification which had no reference to the laws of their nature. But if we classify them as vertebrate or invertebrate, we have classification founded on their organization. Artificial elassification is of no value in science, it is a mere aid to the memory. Natural classification is the foundation of all science. This is sometimes called generalization. It is more properly classification.

The law of gravitation is exemplified in the fall of a single stone to the ground. But many stones and other heavy bodies must have been observed to fall before the fact was generalized, and the law stated. And in this process of generalizing there is involved a principle which experience does not furnish. Experience, how extensive soever it may be, can only give the particular, yet from the particular we rise to the general, and affirm not only that all heavy bodies which have been observed, but that all heavy bodies whether they have been observed or not, gravitate. In this is implied a belief that there is order in “nature, that under the same circumstances the same substances will present the same phenomena. This is a principle furnished by reason, the process founded on it embodies elements furnished by experience.

The results of generalization are general notions expressed by general terms. Objects are classed according to certain properties which they have in common, into genera and species. Hence arose the question which caused centuries of acrimonious discussion. Have genera and species a real, independent existence, or are they only to be found in the mind ?

The principle of generalization is, that beings howsoever different agree or are homogeneous in some respect.

2. From Jeron's Principles of Science, pp. 597–599, ed. 1877.

The term generalization, as commonly used, includes two processes which are of different character, but are often closely associated together. In the first place, we generalize when we recognize even in two objects a common nature. We cannot detect the slightest similarity without opening the way to inference from one case to the other. If we compare a cubical crystal with a regular octahedron, there is little apparent similarity ; but, as soon as we perceive that either can be produced by the symmetrical modification of the other, we discover a groundwork of similarity in the crystals, which enable us to infer many things of one, because they are true of the other. Our knowledge of ozone took its rise from the time when the similarity of smell, at

tending electric sparks, strokes of lightning, and the slow combustion of phosphorus, was noticed by Schönbein. There was a time when the rainbow was an inexplicable phenomenon-a portent, like a comet, and a cause of superstitious hopes and fears. But we find the true spirit of science in Roger Bacon, who desires us to consider the objects which present the same colours as the rainbow; he mentions hexagonal crystals from Ireland and India, but he bids us not suppose that the hexagonal form is essential, for similar colours may be detected in many transparent stones. Drops of water scattered by the oar in the sun, the spray from a water-wheel, the dewdrops lying on the grass in the summer morning, all display a similar phenomenon. No sooner have we grouped together these apparently diverse instances, than we have begun to generalise, and have acquired a power of applying to one instance what we can detect of others. Even when we do not apply the knowledge gained to new objects, our comprehension of those already observed is greatly strengthened and deepened by learning to view them as particular cases of a more general property.

A second process, to which the name of generalization is often given, consists in passing from a fact or partial law to a multitude of unexamined cases, which we believe to be subject to the same conditions. Instead of merely recognising similarity as it is brought before us, we predict its existence before our senses can detect it, so that generalisation of this kind endows us with a


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