Since time immemorial men have been eager to know the prime mover, the cause of all being and of all change, the ultimate substance from which everything stems and which is the cause of itself. Science is more modest. It is aware of the limits of the human mind and of the human search for knowledge. It aims at tracing back every phenomenon to its cause. But it realizes that these endeavors must necessarily strike against insurmountable walls. There are phenomena which cannot be analyzed and traced back to other phenomena. They are the ultimate given. The progress of scientific research may succeed in demonstrating that something previously considered as an ultimate given can be reduced to components. But there will always be some irreducible and unanalyzable phenomena, some ultimate given.
Monism teaches that there is but one ultimate substance, dualism that there are two, pluralism that there are many. There is no point quarreling about these problems. Such metaphysical disputes are interminable. The present state of our knowledge does not provide the means to solve them with an answer which every reasonable man must consider satisfactory.
Materialist monism contends that human thoughts and volitions are the product of the operation of bodily organs, the cells of the brain and the nerves. Human thought, will, and action are solely brought about by material processes which one day will be completely explained by the methods of physical and chemical inquiry. This too is a metaphysical hypothesis, although it supporters consider it as an unshakable and undeniable scientific truth.
Various doctrines have been advanced to explain the relation between [p. 18] mind and body. They are mere surmises without any reference to observed facts. All that can be said with certainty is that there are relations between mental and physiological processes. With regard to the nature and operation of this connection we know little if anything.
Concrete value judgments and definite human actions are not open to further analysis. We may fairly assume or believe that they are absolutely dependent upon and conditioned by their causes. But as long as we do not know how external facts--physical and physiological--produce in a human mind definite thoughts and volitions resulting in concrete acts, we have to face an insurmountable
methodological dualism. In the present state of our knowledge the fundamental statements of positivism, monism and panphysicalism are mere metaphysical postulates devoid of any scientific foundation and both meaningless and useless for scientific research. Reason and experience show us two separate realms: the external world of physical, chemical, and physiological phenomena and the internal world of thought, feeling, valuation, and purposeful action. No bridge connects--as far as we can see today--these two spheres. Identical external events result sometimes in different human responses, and different external events produce sometimes the same human response. We do not know why.
In the face of this state of affairs we cannot help withholding judgment on the essential statements of monism and materialism. We may or may not believe that the natural sciences will succeed one day in explaining the production of definite ideas, judgments of value, and actions in the same way in which they explain the production of a chemical compound as the necessary and unavoidable outcome of a certain combination of elements. In the meantime we are bound to acquiesce in a methodological dualism.
Human action is one of the agencies bringing about change. It is an element of cosmic activity and becoming. Therefore it is a legitimate object of scientific investigation. As--at least under present conditions--it cannot be traced back to its causes, it must be considered as an ultimate given and must be studied as such.
It is true that the changes brought about by human action are but trifling when compared with the effects of the operation of the great cosmic forces. From the point of view of eternity and the infinite universe man is an infinitesimal speck. But for man human action and its vicissitudes are the real thing. Action is the essence of his nature and existence, his means of preserving his life and raising himself above the level of animals and plants. However perishable and [p. 19] evanescent all human efforts may be, for man and for human science they are of primary importance.