There is no scientific evidence whatsoever of the existence of such a third entity, "X," but all our deductions have been by analogy, which proves nothing—that is, by speculation, dreaming, and unavoidably so—since in these conceptions we are close to the border line of the human mind where logical reasoning loses itself in the fog of contradiction. But at the same time there is no evidence against the conception of an entity "X"; it is not illogical, at least no more so than all such general conceptions, no more so than, for instance, that of energy or of matter. As empirical science deals with energy and matter, and entity "X" is neither, it could not be observed by any of the methods of experimental physics or chemistry.
If mind is a third entity, correlated with the entities of energy and of matter, we should expect that mental activity, or entity "X," should occur not only in the highly complex transformations of energy and of matter taking place in the brains of the highest orders of living beings, but that entity "X" should appear in all physico-chemical reactions, just as energy transformations always occur in transformations of matter, and inversely. But this seems not so, and in most of the transformations of energy and of matter entity "X" does not appear. However, we have no satisfactory means of recognizing entity "X," no methods of studying it. Therefore, it may well be that it is noticed only in those rare instances when it appears of high intensity, but in most reactions entity "X" may be so small or appear in such way as to escape observation by the means and by the methods now available. Like energy or matter, entity "X" may have many forms in which it is not recognized by us, just as for a long time the flame was not recognized as the entity energy.
To illustrate, again by analogy: In many transformations of matter, indeed, in most of the more complex ones of the organic world, the concurrent energy transformation is of such slowness and of such low intensity that it appears nonexisting, and can be discovered and measured only by the delicate experiments devised by science. Furthermore, the energy may appear in different forms. Thus the 293,000 J. of energy in equation (2) may appear as heat, or as electrical energy, or as a combination of heat, light, sound, and mechanical energy. Now assume that we could observe and notice only one of the forms of energy—for instance, only electrical energy. We should then find that in the equation (1) we only sometimes get energy—that is, electrical energy—under special peculiar conditions, but usually do not seem to get any of the entity energy, simply because we do not recognize it in the form in which it appears. Analogously, there might be a term of entity "X" in all transformations, even such simple ones as equation (3), but entity "X" may appear in a far different, simpler form. It would mean that "mind" is only one form of entity "X," perhaps the high-grade form, as it appears in highly complex reactions. In the simpler physico-chemical processes of nature, entity "X" also would appear, but in other, simpler forms. It would mean that things such as mind and intellect are not limited to the higher living beings, but characteristics akin thereto would be found grading down throughout all living and inanimate nature. This does not appear unreasonable when we consider that some characteristics of life are found throughout all nature, even in the crystal which, in its mother liquor, repairs a lesion, "heals a wound," or which, in the colloidal solution, may be "poisoned" by prussic acid.
Assume, then, that mind, intellect, personality, the ego, were forms of a third entity, an entity "X," correlated in nature with the entities energy and matter. Then, just as energy and matter continuously change their forms, so with the transformations of energy and of matter, entity "X" would continuously change, disappear in one form and reappear in another form. Entity "X" could therefore not exist permanently in one and the same form, and the permanency of the ego—that is, immortality—would still be illogical, would not exist within the realm of science, but would carry us beyond the limitations of the human mind into the unknowable. Permanency of the ego—that is, individual immortality—would require a form of entity "X," in which it is not further transformable. This would be the case if the transformations of entity "X" are not completely reversible, but tend one definite direction, from lower-grade to higher-grade forms, and the latter thus would gradually build up to increasing permanency. There is nothing unreasonable in this, but a similar condition—in the reverse direction—exists with the transformations of energy. They also are not completely reversible, but tend in a definite direction, from higher- to lower-grade form—unavailable heat energy (the increase of entropy by the second law of thermodynamics). Thus in infinite time the universe should come to a standstill, in spite of the law of conservation of energy, by all energy becoming unavailable for further transformation—that is, becoming dead energy. If entity "X" existed, could it not also have become unavailable for further transformation by reaching its maximum high-grade form and thus become not susceptible to further change—that is, "immortal"—just as the unavailable heat of the physicist is "immortal," and not capable of further transformation? Here we are again in the fog of illogic, beyond the limitations. However, it sounds familiar to the Nirvana of the Buddhist.
Physics and chemistry obviously could not deal with entity "X," and the most delicate and sensitive physical or chemical instruments could get no indication of it, and all attempts at investigation by physical or chemical means thus must be doomed to failure. But such investigations of entity "X" belong to the realm of the science of psychology, or, rather, a broader science, of which psychology is one branch dealing with one form of entity "X," mind, just as, for instance, electro-physics is one branch of the broader science of physics, dealing with electrical energy, while physics deals with all forms of energy.
In concluding, I wish to say that nothing in the preceding speculations can possibly encourage spiritism or other pseudo-science. On the contrary, from the preceding it is obvious that the alleged manifestations of spiritism must be fake or self-deception, since they are manifestations of energy. Entity "X," if it exists, certainly is not energy, and therefore could not manifest itself as such.
FOOTNOTES:
[8] From Harpers Magazine for February, 1922.
[9] It is interesting to note that the relativity theory leads to the conception of a symmetrical four-dimensional world space (Minkowski), in which in general each of the four dimensions comprises space and time conceptions, and the segregation into three dimensions of space and one dimension of time occurs only under special conditions of observation. (AUTHOR.)