=C. Will.=--Consciousness is a state of effort, or will. It was especially pointed out above, that the purposeful consciousness always implies a straining or focusing of consciousness in order to attain a fuller control of the experience. This element of exertion manifest in consciousness may appear as a directing of attention, as the making of a choice, as determining upon a certain action, etc. This aspect of any conscious state is spoken of as a state of _will_, or volition. In the unity of the conscious life, therefore, there are three attitudes from which consciousness may be viewed: 1. It is a state of Knowledge, or of Intelligence. 2. It is a state of Feeling. 3. It is a state of Will. On account of this threefold aspect of mental states, consciousness has been represented in the following form: [Illustration] The significance of comparing the threefold aspect of consciousness to the three sides of a triangle consists in the fact that if any side of a triangle is removed no triangle remains. In like manner, none of the three attributes of consciousness could be wanting without the conscious state ceasing to exist as such. No one, for instance, could feel the pressure of a tight shoe without at the same time knowing it, and fixing his attention upon it. Neither could a person at any particular time know that the shoe was pinching him unless he was also attending to and feeling the experience. CHAPTER XX MIND AND BODY =Relation of Mind to Bodily Organism.=--Notwithstanding the antithesis which has been affirmed to exist between mind and matter, yet a very close relation exists between mind and the material organism known as the body. There are many ways in which this intimate connection manifests itself. Mental excitement is always accompanied with agitation of the body and a disturbance of such bodily processes as breathing, the beating of the heart, digestion, etc. Such mental processes as seeing, hearing, tasting, etc., are found also to depend upon the use of a bodily organ, as the eye, the ear, the tongue, without which it is quite impossible for the mind to come into relation with outside things. Moreover, disease or injury, especially to the organs of sense or to the brain, weakens or destroys mental power. The size of the brain, also, is found to bear a certain relation to mental capacity; the weight of the average brain being about 48 ounces, while the brain of an idiot often weighs only from 20 to 30 ounces. THE NERVOUS SYSTEM [Illustration: Brain and Spinal Cord]