The class of mental states or processes grouped together under the name of “intellectual processes,” forms the second great division of the mental states, the two others being “feeling” and “will,” respectively.
“Intellect” has been defined as follows: “The part or faculty of the human mind by which it knows, as distinguished from the power to feel and to will; the thinking faculty; the understanding;” also as “that faculty of the human mind by which it receives or comprehends the ideas communicated to it by the senses or the perception, or other means, as distinguished from the power to feel and to will; the power or faculty to perceive objects in their relations; the power to judge and comprehend; also the capacity for higher forms of knowledge, as distinguished from the power to perceive and imagine.”
In the preceding chapters we have seen that the individual is able to experience sensations in consciousness, and that he is able to _perceive_ them mentally, the latter being the first step in intellectual activity. We have also seen that he is able to reproduce the perception by means of memory and imagination, and that by means of the latter he is able to re-combine and rearrange the objects of perception. We have also seen that he has what are known as “feelings,” which depend upon his previous experience and that of his progenitors. So far the mind has been considered merely as a receiving and reproducing instrument, with the added attachment of the re-combining power of the imagination. Up to this point the mind may be compared to the phonographic cylinder, with an attachment capable of re-combining its recorded impressions. The impressions are received and perceived, are stored away, are reproduced, and by the use of the imagination are re-combined.
Up to this point the mind is seen to be more or less of an automatic, instinctive faculty. It may be traced from the purely reflex activity of the lowest forms of life up through the lower animals, step by step, until a very high degree of mental power is perceived in animals like the horse, dog, or elephant. But there is something lacking. There is missing that peculiar power of thinking in symbols and abstract conceptions which distinguishes the human race and which is closely bound up with the faculty of language or expressing thoughts in words. The comparatively high mental process of the lower animals is dwarfed by the human faculty of “thinking.” And _thinking_ is the manifestation of the intellect.
What is it to _think_? Strange to say, very few persons can answer this question correctly at first. They find themselves inclined to answer the inquiry in the words of the child: “Why, to think is to _think_!” Let us see if we can make it plain. The dictionary definition is a little too technical to be of much use to the beginner, but here it is: “To employ any of the intellectual powers except that of simple perception through the senses.” But what are the “intellectual powers” so employed, and how are they employed? Let us see.
Stating the matter plainly in common terms, we may say that “thinking” is the mental process of (1) comparing our perceptions of things with each other, noting the points of likeness and of difference; (2) classifying them according to the ascertained likeness or difference, and thus tying them up in mental bundles with each set of “things of a kind” in its own bundle; (3) forming the abstract, symbolic mental idea (concept) of each class of things, so grouped, which we may afterward use as we use figures in mathematical calculations; (4) using these concepts in order to form _inferences_, that is, to reason from the known to the unknown, and to form judgments regarding things; (5) comparing these judgments and deducing higher judgments from them; and so on.
Without thinking, man would be dependent upon each particular experience for his knowledge, except so far as memory and imagination could instinctively aid him. By thought processes he is enabled to infer that if certain things be true of one of a certain kind of things, the same thing may be expected from others of the same class. As he is able to note points of likeness or difference, he is able to form clearer and truer inferences. In addition, he is able to apply his constructive imagination to the rearrangement and recombination of things whose nature he has discovered, and thus progress along the line of material achievement as well as of knowledge. It must be remembered, however, that the intellect depends entirely for its material upon the perception, which in turn receives its raw material from the senses. The intellect merely groups together the material of perception, makes inferences, draws conclusions from, and forms conclusions regarding, them, and in the case of constructive imagination recombines them in effective forms and arrangement. The intellect is the last in order in the course of mental evolution. It appears last in order in the mind of the child, but it often persists in old age after the feelings have grown dim and the memory weak.
What is known as the “concept” is the first fruit of the elemental processes of thought. The various images of outside objects are sensed, then perceived, and then grouped according to their likenesses and differences, and the result is the production of concepts. It is difficult to define a concept so as to convey any meaning to the beginner. For instance, the dictionaries give the definition as “an abstract, general conception, idea, or notion formed in the mind.” Not very clear this, is it? Perhaps we can understand it better if we say that the terms dog, cat, man, horse, house, etc., each expresses a concept. Every term expresses a concept; every general name of a thing or quality is a term applied to the concept. We shall see this a little clearer as we proceed.
We form a concept in this way: (1) We _perceive_ a number of things; (2) then we notice certain _qualities_ possessed by things–certain properties, attributes, or characteristics which make the thing what it is; (3) then we _compare_ these qualities of the thing with the qualities of other things and see that there is a likeness in some cases, in various degrees, and a difference in other cases, in various degrees; (4) then we _generalize_ or _classify_ the perceived things according to their ascertained likenesses and differences; (5) then we form a _general idea_ or _concept_ embodying each class of thing; and, finally, we give to the concept a _term_, or _name_, which is its symbol.
The concept is a _general idea_ of a class of things; the _term_ is the expression of that general idea. The concept is the idea of a class of things; the term is the _label_ affixed to the thing. To illustrate this last distinction, let us take the concept and term of “bird,” for instance. By perception, comparison, and classification of the qualities of living things we have arrived at the conclusion that there exists a great general class the qualities of which may be stated thus: “Warm-blooded, feathered, winged, oviparous, vertebrate.” To this general class of quality-possessing animals we apply the English term “bird.” The name is merely a symbol. In German the term is _vogel_; in Latin, _avis_; but in each and every case the _general idea_ or _concept_ above stated, _i.e._, “warm-blooded, feathered, winged, oviparous, vertebrate,” is meant. If anything is found having all of those particular qualities, then we know it must be what we call a “bird.” And everything that we call a “bird” must have those qualities. The term “bird” is the symbol for that particular combination of qualities existing in a thing.
There is a difference between a mental image of the imagination and a concept. The mental image must always be of a _particular_ thing, while the concept is always an idea of a _general class_ of things which cannot be clearly pictured in the mind. For instance, the imagination may form the mental picture of any known bird, or even of an imaginary bird, but that bird always will be a distinct, _particular_ bird. Try to form a mental picture of the general class of birds–how will you do it? Do you realize the difficulty? First, such an image would have to include the characteristics of the large birds, such as the eagle, ostrich, and condor; and of the small birds, such as the wren and humming bird. It must be a composite of the shape of all birds, from the ostrich, swan, eagle, crane, down to the sparrow, swallow, and humming bird. It must picture the particular qualities of birds of prey, water birds, and domestic fowls, as well as the grain eaters. It must exhibit all the colors found in bird life, from the brightest reds and greens down to the sober grays and browns. A little thought will show that a clear mental image of such a concept is impossible. What the most of us do, when we think of “bird,” is to picture a vague, flying shape of dull color; but when we stop to think that the term must also include the waddling duck and the scratching barnyard chicken, we see that our mental image is faulty. The trouble is that the term “bird” really means “all-bird,” and we cannot picture an “all-bird” from the very nature of the case. Our terms, therefore, are like mathematical figures, or algebraic symbols, which we use for ease, speed, and clearness of thinking.
The trouble does not end here. Concepts not only include the general idea of _things_, but also the general idea of the _qualities of things_. Thus sweetness, hardness, courage, and energy are concepts, but we cannot form a mental image of them by themselves. We may picture a sweet _thing_, but not sweetness itself. So you see that a concept is a purely abstract mental idea–a symbol–akin to the figures 1, 2, 3, etc., and used in the same way. They _stand_ for general classes of things. A “term” is the verbal and written expression of the general idea or concept. The student is requested to fix these distinctions in his mind, so as to render further understanding of them easy.