senses, is recalled as an individual object. The memory and the imagination can only call up and paint to the mind each single object as it was presented. But the next operation of the mind, which is reflection, or thinking, classifies objects. We put them together in a class, because they have common qualities. We thus get common nouns, as we call them, or, to use a philosophic term, we get concepts, or notions. The process to which we should otherwise be subjected we abridge, by giving one name to a great multitude of objects, as animal, man, tree, river. This involves profound processes of reflection. We have to find the common qualities, and think of them only, and classify our objects from those common qualities.

We

Then we carry this process farther. We form a proposition. We predicate of a concept certain qualities, or we deny those qualities to the object. thus get further knowledge of objects by our classification, or we can place them in a class for further use. Thus, we are constantly making assertions, or declaring the character of things. Almost all the opinions which we express, are of this character. We are classifying them, and by our classification we assert certain qualities to belong to them. We say, for instance, that the orbit of a planet is an ellipse. We have here three concepts; namely, the planet, the orbit, and the ellipse. The passage of a planet

around the sun is a certain path. All such paths we call by the common name, orbit. The stars which have been discovered to move around the sun, we call planets. Then we take a cone, and make a section at a certain angle to its axis, and we get a figure which has certain properties. All curved lines which have these properties we name ellipses. We have found that the path in which a planet moves, has these qualities. So we identify this path with this mathematical curve. This process is a very great abridgment of our knowledge, and enables us to keep it clearly before our minds. Thus, by means of common nouns or concepts, we have a vast quantity of knowledge placed away in our minds. And when we form these concepts into propositions, we greatly enlarge our knowledge, and we put it into a form for future use, as well as into a form in which we can more clearly see it.

The mind then performs another operation, which we call reasoning. By reasoning, we extend our knowledge of what is observed, to that which is not observed. By the two processes of induction and deduction, we learn much that we could not learn by observation. Thus, Kepler found from the observations furnished him by Tycho Brahe, that each planet moved in an ellipse. Newton demonstrated that gravity, acting inversely as the square of the distance, must cause a planet to move in such a curve.

I

It was long a question in debate, whether gravitation operated beyond the solar system; but when Sir John Herschel discovered that some of the stars, which had been regarded as fixed, had a motion with regard to another star, and that this motion was in an ellipse, the conclusion was established that gravitation, acting inversely as the square of the distance, was the law of operation beyond the solar system. By induction we establish from a small number of cases a law which applies to a large number, or to all the cases. So in deductive reasoning, we come to predicate of a concept certain qualities, or certain characteristics. It is beyond our observation that these qualities or characteristics belong to another object or class; but it may be within our power to show that this object or class may be included in the class of which we are able to predicate the qualities or character, and we can then, without observation, affirm that these qualities or characters belong to the object or class.

Thus, by this process, we are constantly throwing light on certain objects, or concepts, or classes of objects. We are constantly extending our knowledge. We multiply it by the process of reasoning.

This is the first function which the human mind 'performs; namely, the acquiring knowledge by these

History of the Inductive Sciences, vol. i. book 7, p. 564, Double Stars. W. Whewell, D.D.

processes.

This is one of the characteristics of man. It marks his character, and separates him from all other animals. He has marks which they have not. He, in this respect, has a different nature from them. This nature puts him into certain relations, and creates obligations and responsibilities, which cannot exist in animals which have not this nature. The relation of knowledge and the capacities for knowledge to morality will be considered hereafter. We are now only inquiring what is the nature of man; what kind of a being he is; and therefore, what kind of actions he performs.

II. Having looked at the intellectual side of man's nature, we must consider the emotional side. Man is a being that perceives and reflects, but he is also a being that is moved to action by certain principles in his physical and psychical nature. There are certain states of the body, and certain states of the soul, which stimulate the will, or which move and influence us to choose and decide on a certain course of action, or which cause us to perform any act whatever. It is not only knowledge, it is not only the perception of certain things and qualities and acts and relations, which moves us. We can conceive an intelligent being to be without feeling, and to view with the greatest indifference, and without an emotion, the objects which his intellect has perceived. But man is not such a being. He is as capable of

feeling, and of being moved by feeling, as he is of perceiving the existence of things and the relations of things. His knowledge is accompanied by emotion, and he is moved by his feeling to act. Thus, a person may see a ravenous beast of the forest, and, if unprotected, the perception brings with it fear and terror. We say that we shudder at the sight. And we say further, that this sense of fear, which is part of our nature, and which contributes towards making us the beings that we are, is necessary for our safety; and, unless it was joined with our intelligence, the race of man could not exist. So the mere knowledge that food and drink and heat and exercise are also necessary for our existence, would not induce us to take the proper care of ourselves, to preserve our life, or to maintain our health. There are implanted in us certain bodily desires, which move us to act, which create in us certain feelings of uneasiness and discomfort which can be allayed only by their proper object.

In studying the nature of man, we must, then, study this part of his nature, and learn from it the manner in which he is stimulated to action.

The analysis of this part of our nature is confessedly difficult.' There have been various attempts

For classification, see Dugald Stewart, Philosophy of the Active and Moral Powers, vol. i. book 1; W. Whewell, D.D., The Elements of Morality, book 1, chap. ii.; also, Supplement to Fourth Edition, chap. i.; J. McCosh, D.D., LL.D., The Emotions, book 2, chap. i.