LECTURE VII.

THE NATURE AND ORIGIN OF IDEAS.

1. The Various Kinds of Reasoning.

It may be well to state before going further, that the laws and formulæ of reasoning depend upon the nature and relations of the things we reason about, and are, in all cases, to be derived like the truths of mathematics, a priori from a consideration of the nature of that about which we are reasoning.

We may have reasoning (1) by analysis, and (2) by synthesis..

1. We reason by analysis, whenever we analyze an object and show that, from its very nature, a certain proposition concerning it must be true. Thus if we prove from a triangle, that there must be three sides, as well as three angles, or form the nature of a circle that its radii must be equal, we have examples of analytic reasoning. Or if we reason from the nature of an extended object that it must be divisible we have another example of the same kind.

From this it will appear that all reasoning at the outset and in its first stages must be analytic, or begin with analysis: it either begins by making the analysis or by supposing one already made.

2. Synthetic reasoning depends, not as analytic does on the

nature of the object reasoned about, but on the relation of two or more objects to each other.

Of this there may be five cases.

(a.) When we have two nouns denoting the same object. In this case the two supposed objects are in reality identical, one and the same.

(b.) In the next case--and this is the most comprehensive of all the objects are related as individual and class, or as one class comprehended in another, as John is an individual in the class man, but men are also included in the higher class animals, and so on. Every object, real or conceivable, sustains such a relation to species and genera.

(c.) The third relation is that of cause and effect. Everything we know of sustains the relations of cause to something else-some thing or change in the condition of a thing. And so too everything except One is an effect of something else. Hence reasoning from cause to effect and the converse from effect to cause is of universal application.

(d.) The next kind of reasoning is by way of number and quantity. Of this kind is all Arithmetic, Geometry, and in fact every branch of Mathematics. It is true, we profess and appear to be dealing with "units" and "lines," etc. But the units are considered as numbers and lines as quantities. And even lines may be considered as made up of points or parts, and thus subject to the laws of number. Hence, Analytics and the Calculus.

(e.) The fifth and last relation of objects, is that of parts to a whole. This is the most obscure and least understood of all kinds of reasoning. In a class on which the kind 1 b. depends. We have the fundamental law that any property that can be affirmed of a class, may be affirmed of any individual or smaller class, contained in that class. Thus, if all men are fallible, it may be said of any man, or class of men, that he is, or they are, fallible. And on the other hand, it holds, that any property that can be affirmed of all the individuals in the class may

be affirmed of the class. Thus if we can say of each man that he is a rational being, we can say of any class of men, or of all men, as a genus, that they are rational.

But in the relation of parts to a whole, neither of these conditions holds good. Chemistry is an example. No man can tell before hand, what will be the properties of a new compound, though he may know the properties of each element that is to enter into it. Nor yet can he tell before analysis, whether the elements will be gaseous or solid, metallic or nonmetallic.

And the same is true of all "collective wholes." Every member of a society may be a christian man, and yet the society itself, be it a bank, a railroad, or an insurance company, we should hardly call it a christian society; still less perhaps, unchristian or anti-christian. A body of believers duly organized is a church, but yet, no one of them would be called when separately considered, a church.

Hence it must be obvious, that reasoning from parts to wholes, and the reverse, from wholes to parts, is one of the most risky kinds of reasoning, though there are cases in which it is not only the best, but the only one we can have.

The 1 and 2 d are the only two kinds of reasoning that enter into Mathematics, and their application to certain facts or definitions make up the whole of Mathematics.

The 1 and 2 b and c, are the methods of the Natural Sciences. We depend on Analysis in the sense here used, for only the axioms-as for example: No particle of matter at rest, will change its condition in that respect, of itself—but will move and be moved, only as it is acted upon by something else. Or this other, in Chemistry, neither in analysis nor synthesis can we either create or destroy a single atom of mat

ter.

The 2 b. classification, is chiefly the method in Botany, Zoology and Chemistry. 2 c. is prominent in the physics and mechanics. 2 a. is largely in use in the grammatical and philological sciences.

And 2 e, enters most largely into the social and political sciences, where we have to deal with wholes that are made up of individuals, each having a nature and will of his own-which is nevertheless greatly modified by the influence of, and necessities for, combined and associate action.

Chemistry is also working towards a condition of maturity and perfection in which not only the facts of the science will have been well and exhaustively ascertained-but in which we may be able to reason from wholes to their elements, and from our knowledge of the elements to the nature of such compounds or combinations as they may be forced into makingand even to conditions of matter that are nowhere now, within the reach of observation and experiment. And possibly, the question of the origin of life, by spontaneous generation, may then be settled by a priori reasoning, as the question of perpetual motion has already been settled.

2. Cousin's Theory of the Origin of Ideas.

In the last Lecture I gave the common conception of Knowledge as made up of ultimate parts or particles, and stated the six most important theories of the origin and nature of those elements, in order to prepare the way to call attention to the fact of Insight-which, it seems to me, has been overlooked or ignored in all preceding discussions of the origin of knowledge -in a way and to an extent which seems, whenever we think of it, to be quite incredible.

We are not however, quite through with the questions that relate to ideas, I have spoken of them as though the word "idea" were equivalent to "thought," and have, consequently, treated them as a species of objectified abstractions. But this view will not quite suit all that has been said about them, or all the theories that have been held concerning them.

I cannot understand the words Plato used in the Parmenides, referred to in Lecture VI, § 6, without supposing that he

more.

meant something more than and different from, mere objectified thoughts. In fact his whole theory implies something It is true that the statement that he identified the properties of the objects we see with ideas-or rather made them one and the same thing, seems too absurd to be credible. But certainly the mediæval Realists, John Scotus, Anselm, and Aquinas, as well as the modern Idealists, Berkeley and Fichte, have done so. If one asks" is whiteness," for example, "a proper"ty of the paper, or an idea in the mind?" this whole theory implied that it is an idea. To prove this the two most carefully elaborated works-of Berkeley and Fichte--the "Dia"logues between Hylas and Philonous," of Berkeley, and the Bestimmung des Menschen" of Fichte-were written. It is true that, in terms they spoke of and attempt to prove the identity of our sensations and the properties of objects as was implied in the quotation from Huxley, (Lecture IV, § 21.) But then "sensations" are soon transformed into ideas, or the one word is in fact substituted for the other in the farther prosecution of the subject.

The Realists held that any property--as whiteness," "hard"ness," "humanity," "corporiety," and so of all the rest, are not only ideas-but are also the "essence" of things. They are of course in us, our own minds. They would say, and in fact did teach, as Plato had done before them, that if we would learn anything of men individually-of this and that man--we must use our eyes and look at them. But if we would learn anything of the class or genus man-that is of mankind generally, or in general--we must look, by an act of intuition, at the idea-humanity-that is within us. And what they thus held of humanity, they held and taught with regard to all simple properties. They made the whiteness to be an idea in us, rather than a property or attribute of external objects. Absurd as this may seem there is no way of understanding the words they use, or the arguments they advance, without attaching this meaning to their words.