3. DEPENDENCE OF REASONING UPON LAWS AND PRINCIPLES, EMPIRICAL THINKING And Reasoning COMPARED. The second characteristic line of differentiation between reasoning and ordinary thinking is to be found in the larger amount of analysis involved and the greater dependence of the movement of thought upon the recognition of laws and principles. Perhaps this larger amount of analysis is itself only an aspect of the process of attempting to control the thinking by reference to laws. The situation needs to be analyzed more carefully in order to discover at just what point law is involved. The view of reasoning as thinking controlled by reference to laws and principles may be made clearer by entering upon a discussion of the difference between empirical thinking and reasoning.

(1) Illustrated in dealing with flickering gas flame.

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Mr. James cites the case of trying to remedy a flickering gas flame by one who is not familiar with the principle in accordance with which gas burns. Such a person might accidentally discover that by raising the chimney of the lamp a little at the bottom the flame burned more smoothly. Now, when he has difficulty with the flame again his remedy for the situation will be found through going back in memory and taking bodily the method of procedure which worked in the past and applying it to this situation. He will raise the chimney slightly and put something under it to hold it in that position. In so far as he has met the situation by thinking at all, this type of thinking would be called empirical. The situation confronting him has not been analyzed and the method of solution has been presented to consciousness through reproductive imagination. There has been little or no reconstruction. But suppose he had been familiar with some of the simplest laws of combustion. He would not have needed to experiment blindly in the first place to find a remedy. He would have immediately inferred that there was an insufficiency of oxygen, and that 'James, Psychology, Briefer Course, p. 359.

something must be done to provide a greater supply. On the basis of this inference, he would have raised the chimney slightly at once or have taken advantage of some device in the burner for supplying more air to the flame. His method of solution of the problem is determined by an analysis of the situation and the application of a law in accordance with which he constructs a method of procedure without experimentation or without previous experience in doing this particular thing.

(2) Illustrated in the procedure of medicine.

Empirical thinking is well illustrated in the procedure of early medicine. Certain herbs are found as the result of repeated experiences to be beneficial in certain kinds of sickness. When some one is ill, the illness is taken pretty much in the large as presenting a problem of a certain general type. This problem is solved by going back into past experience for the remedy. The remedy is taken as more or less of a ready-made affair, and it is applied in a series of steps the order of which is practically the same as that used on some previous occasion. There is no minute analysis of the problem nor of the remedy, and there is no careful and reflective adjustment of means to ends through thoroughgoing reconstruction of the mode of procedure to meet the specific conditions of the case in hand. The method of procedure is determined by a rule and not by the application of principles.

The trained physician of to-day approaches cases of sickness in a different way. Let us say that this case of sickness shows many superficial evidences of being a fever. But this does not immediately suggest a method of treatment taken bodily, or with little modification, from past experience. There are many different sorts of fever. Before prescribing for this case it must be analyzed more fully. It cannot be taken en bloc. Symptoms must be observed more carefully and inferences drawn from them. Furthermore, not all patients are exactly alike. The prob

lem is quite different for people of different bodily conditions and of different temperaments. Before the physician can understand the exact nature and the degree of seriousness of the disease or of the kind and strength of the medicines he may use, he may have to make a thorough investigation of the present physical condition of the patient. Every vital organ may have to be examined. He may even have to go beyond this and seek information concerning his patient's heredity, his habits, and his manner of life in general. Before he can determine a mode of procedure which shall represent an adequate solution of his problem the physician must have a minute and detailed knowledge of his patient, of the chemical constituents of his medicines, of the structure and function of the various organs of the body, and of the specific effects of the properties of his medicines upon the action of the bodily organs. On the basis of his analysis of the whole given situation, taking account of all the elements of the problem and their relation to one another, he may construct a method of procedure specifically adapted to this particular case, even if he has never had a case just like it before. His method of procedure, his solution of the problem, is largely determined by his knowledge of laws and principles of human physiology and of the effects of drugs and other remedies upon the functions of the organs of the body. Of course, the scientific physician can never get completely away from certain empirical elements, nor can he fail to reap great advantages from abundance of experience; yet it is true in a sense that he virtually constructs anew his method of procedure for every case that he treats. He is a reasoner as distinguished from an empirical thinker.

(3) Illustrated in the procedure of agriculture.

In agriculture we see this same transition from empirical modes of dealing with its problems to scientific methods. The change is due to the formulation of laws and principles of lant growth, of the reactions of soils, etc. Again, along

with the formulation of laws and principles, there goes the recognition of the need of getting at the details of a situation. This makes problems specific and individual, while at the same time they fall under general principles. But, while general principles apply, the method of procedure must be worked out to suit the particular case. This process of attacking problems of agriculture not by rules of procedure determined wholly by past experience, but through the application of laws and principles to situations thoroughly analyzed, involves reasoning as over against empirical thinking. This will be made clearer in the illustrations which follow.

Farmers in many parts of the country once maintained the fertility of their soil by the rotation of crops. They plowed up grass land and planted it to corn or potatoes. The following year it was devoted to oats, and the next year it was sown to wheat. With the wheat, grass seed was sown, so that upon the harvesting of the wheat crop the land reverted to meadow once again. After taking off a few crops of hay, the rotation began once more. It was found that in this way better crops were produced than could be secured by raising the same crop upon the same field continuously. But the reason why the fertility of the soil was better maintained in this way was not known by many of those who followed the practice. The method of procedure was not constructed on the basis of a knowledge of underlying principles which made it valid. The same was true of the custom of plowing under green crops, such as clover and rye, and of the use of manure. The justification of these modes of procedure lay in their repeated success in previous experience as methods of maintaining the fertility of the soil. The methods were empirical rather than scientific; and the thinking involved in their use was empirical rather than reasoning. When the chemical nature of the soil has been accurately determined, the chemical constituents of various plants have been discovered, and

we know just what each crop takes from the soil and what it contributes to its enrichment, then it is possible reflectively to devise ways and means of adjusting crops to the soil and to one another in the agricultural process. In other words, the problems can be solved by reasoning; for exact knowledge of the essential factors entering into them can be secured, and laws and principles can be applied in the construction of methods of procedure.

4. DEFINITION OF REASONING.

Having pointed out the specific differentia of the reasoning process, we are now ready to define reasoning from that point of view. Reasoning is controlled thinking,— thinking organized and systematized according to laws and principles and carried on by the use of superior elements of technique.

5. BIOLOGICAL SIGNIFICANCE OF REASONING.

(1) Reasoning the highest factor of control.

The great problem of living creatures in their evolution from lower to higher forms is that of control over their environment. That form of control is most valuable in which the individual is able to manipulate elements of his environment in such a way as to make them serve as means to the realization of his own ends. The conscious processes are significant in the life of the organism on this very account. Reasoning is the culmination and summation of all the conscious processes in so far as they may be conceived as control phenomena. All thinking is essentially constructive in its nature. As it approaches that stage of development and organization which we call reasoning, it enables the individual to deal more and more effectively with new situations, thus enlarging and expanding his field of control over the world in which he lives. Furthermore, reasoning simplifies the process of solving the problems which confront the individual. Reasoning moves toward the solution of its problems in the most direct line. The