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Mr. Ward's method of reasoning. Any hypothesis concerning the basis of mental and social life is legitimate if it really adds to our knowledge or helps us to see more clearly their relations and importance. The method of an author must be judged, however, by more general principles than those used to judge of any particular hypothesis. And this necessary part of good reasoning has been so generally neglected, except in political economy, that it is only with difficulty that the bearing of such discussions can be made evident to persons who assume that there is only one scientific method, and that the method of the physical science with which they are familiar. It is commonplace to distinguish between the deductive and inductive methods, and if the classification of method is carried no farther, this distinction has little value. The fact is, that there are many kinds of deductive and of inductive methods, and we must have more definite knowledge of a given method than these terms will impart before we can judge of its validity.
The first method of reasoning I wish to describe is used by writers like Mr. Ward who believe that the universe has at its basis some simple element and that all phenomena are due to the effects produced by this element in its various combinations. Whether this element be matter, force or energy is of no consequence at present, as we are interested not in questions of fact, but only in those of method. The simple forces these writers tell us are those dealt with in physics, the chemical forces are next in order of complexity, then come the vital forces of biology, next the psychic forces, and finally the social forces. There is from this point of view a hierarchy of the sciences, each of which deals with a particular class of forces. If this thought be accepted, the tendency is to assume a bold form of deductive reasoning and to make our knowledge of any science depend upon deductions made from the facts and forces of the underlying sciences. Chemistry thus becomes a form of physics, biology becomes a combination of physics and chemistry and has its
laws verified, not by inductions within the field of biology, but by deductions from physical or chemical premises. To a still greater degree psychology and sociology lose their independent character as fields of investigation and become the battle-ground for circuitous deductions based upon the facts of physics, chemistry and biology. Analogy and deduction take the place of true induction within the rcalm of psychology and sociology. This long-distance method of reasoning has a great charm for many minds and constitutes one of the erroneous features of the reasoning of biologic sociologists.
The second method of reasoning is popular in biology, although not peculiar to it. Scientific inquiry may begin with a knowledge of given causes, and from them reason to their effects by a process of deduction; or it may begin with a knowledge of the effects of which the causes are unknown, and then the inquiry is as to the laws which determine the visible, known effects. Biology is a science of the latter class. The organisms which the biologist studies are the result of an evolution due to the adjustment of these organisms to their environment. The biologist studies the record of the effects of this adjustment as shown in the development of I animal life and infers what their causes are. Geology is a similar science. The crust of the earth is the record of the changes and effects which unknown and unseen forces have produced in distant ages. History is also a science of this class. The written records of past civilization are studied in the hope of discovering the causes which produced the recorded events. Comte believed that this was the only true method of inquiry and bases his theory of a positive science upon it.
The third method of reasoning which I wish to emphasize is that used by economists, although it is not characteristic of them alone. It represents merely a certain stage in the process of the development of any science when it is passing from a purely inductive phase of inquiry to a purely deductive
phase. The essential features of this method are that first inductions are made, based upon a direct observation of the phenomena in question, and then these inductions are used as premises from which deductions are made as to other facts. Both the inductions and deductions lie within the realm of the science and the inductions precede and determine the deductions. There are no long-distance deductions from underlying sciences which shut out or do away with direct observation and induction. Economics thus differs radically from physics, which deals largely with long-range deductions from unseen causes and from biology which has merely a record of effects from which to infer causes. The causes
in economics are apparent and may be discovered by direct investigation. The reasoning is thus from cause to effect, and not from effect to the cause. It is therefore a true deductive science, free from those suspicious long-range deductions from the realm of other sciences which at present are so characteristic of physical speculations.
The errors in Mr. Ward's reasoning are due to a combination of the first two methods, and to a neglect of those precautions which a thorough knowledge of the third method of reasoning would insure. If he were as familiar with the results of economic investigation as he is with those of biology and physics, he would be a safer guide. His arguments on social affairs begin with certain long-range deductions from the physical sciences which in the so-called hierarchy of the sciences precede social science.* If these deductions were verified by inductions within the realm of the social sciences, the procedure would be legitimate. At this point, however, Mr. Ward swings over from the first to the second method of reasoning. He now becomes a biologist, and uses the
"The power of co-ordinating facts can only be acquired by their study in relation to more general truths. These general truths are to be found, not in the science to which the facts belong, but in the more general sciences to which this is subordinate. In a word, the details of each science can only be generalized by referring them to the laws of the science next above it in the hierarchy." Ward's "Dynamic Sociology," vol. i., p. 135.
biologic method of inferring the causes from the effects. Social and psychic phenomena influence bodily actions and determine in many ways the course of biologic development. Mind and society, we are told, are not objective facts which can be studied directly, but their activities must be inferred from the results. We can know them only through the mechanical effects they produce. A series of long deductions from other sciences makes the basis for the social sciences, and then the verification of the principles which are given to the social sciences by these deductions is secured through the effects which they are supposed to have in the biologic world. We thus have, to speak generally, three points, A, B and C, which represent three fields of investigation. B is said to depend on A, an underlying science, and gets its principles from deductions about the phenomena of A. As C is produced largely as the result of B, we can verify the assumed deductive principles of science B by their effects in the field of science C. We can on this hypothesis proceed without any direct knowledge of science B. All we need to know of it can be learned through sciences A and C. Thus, by shifting from long-range deductions to inferences from effects we can create a science without any direct knowledge of its content. Surely the hierarchy of the sciences is a useful institution if it can help us over difficulties in so easy a fashion.
It is hardly necessary to state that no science has ever been developed on this plan. Valuable inductions have been made within the realm of each science before the deductive epoch began. Kepler's laws, and a mass of work even more inductive in character, preceded the discoveries of Newton, by which physics was changed into a deductive science. Chemistry did not succeed until attempts to deduce chemical laws from the principles of physics were abandoned, and a series of inductions based on direct observation of chemical changes was substituted in their stead. In biology also the theory of evolution was proved by an inductive study of biologic facts.
The recent long-range deductions based on physical facts is a subsequent growth.
Yet at every stage in the progress of the physical sciences the method which Mr. Ward uses has been tried and has proved a failure. The cause of these errors may be ascribed to two pre-suppositions to which the scientific mind is peculiarly liable.
In the first place a long continued study of the phenomena of any science cramps, if it does not destroy, the imagination of the student and thus creates the habit of viewing the phenomena of other sciences as though they were mere varieties of those facts with which the scientist is most familiar. Doubtless the concept of a common simple element underlying all phenomena is useful, but when it assumes the concrete form which the study of particular classes of facts gives it, it becomes a dangerous error.
This restraining influence of a defective imagination shows itself most plainly when the scientist becomes a student of mental phenomena. Mr. Ward, for example, is very clear in his explanations so long as he deals with the nervous or vital processes. He describes in a skillful way the cell structure, and traces the nervous currents from their origin to their final culmination in bodily activity. But when he leaves the physical side and tries to describe mental processes, his descriptions become vague, and he is unable to break away from the concepts which were useful in his biologic studies. He compares the phenomena of life and those of mind to the obverse and reverse sides of a coin. If the vital side of mind may be called the obverse side, Mr. Ward's description of it is excellent, but the reverse or purely mental side is simply a copy of the vital side minus the visible characteristics which mental phenomena lack. He cannot imagine the mental forces to assume any other form than the vital currents and reactions take on. His mental phenomena are merely ghosts of the biologic world. They act and react, march and countermarch, with all the