Читать книгу The Dawn of Reason; or, Mental Traits in the Lower Animals - Jr. James Weir - Страница 16

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Mind is a resultant of nerve, in the beginning of life, neuro-plasmic, action, through which and by which animal life in all its phases is consciously and unconsciously, directly and indirectly, maintained, sustained, governed, and directed.

This definition of mind is widely different from the definition of those metaphysical scientists who directed psychological investigation and observation a decade ago. They held that psychology had nothing in common with physiology and morphology; that psychos stood upon an independent pedestal, and was not affected by, and did not affect, any of the phenomena of life.

In these days it is becoming an accepted fact that morphology, physiology, and psychology are intimately related and connected, and that a thorough knowledge of the one implies an equally thorough knowledge of the others.

Morphology and physiology, until a comparatively recent time, led divergent paths; but, thanks to such men as Haeckel, Romanes, Huxley, Wolff, and many others, this erroneous method of investigation, to a great extent, has ceased.

"The two chief divisions of biological research—Morphology and Physiology—have long travelled apart, taking different paths. This is perfectly natural, for the aims, as well as the methods, of the two divisions are different. Morphology, the science of forms, aims at a scientific understanding of organic structures, of their internal and external proportions of form. Physiology, the science of functions, on the other hand, aims at a knowledge of the functions of the organs, or, in other words, of the manifestations of life."[1]

Indeed, physiology has so diverged from its sister science, morphology, that it completely and entirely ignores two of the most important functions of evolution, heredity and adaptation. This has been clearly shown by Haeckel, who has done much towards bringing about a change of opinion in these matters.[2]

Morphology and physiology are interdependent, correlated, and connected one with the other; and, as I will endeavor to point out as my argument develops itself, psychology is, likewise, intimately associated with these two manifestations of life.

It will be noticed that as forms take on more complexity, and as organs develop new and more complex functions, psychos becomes less simple in its manifestations, and more complex in its relations to the internal and external operations of life.

Keeping in view the definition of mind as advanced in the opening paragraph of this chapter, it at once becomes evident that even the very lowest forms of life possess mind in some degree. It is true that in the monera, or one-celled organisms, the nerve-cell is not differentiated; consequently, if I were to be held to a close and strict accountability, my definition of mind would not embrace these organisms. Yet, some small latitude must be allowed in all definitions of psychological phenomena, especially in those phenomena occurring in organisms which typify the very beginnings of life.

I am confident that, notwithstanding the fact that the nerve-cell is not differentiated in these primal forms, nerve-elements are, nevertheless, present in them, and serve to direct and control life.

Mind makes itself evident in two ways—consciously and unconsciously. The conscious manifestations of mind are volitional, while the unconscious, "vegetative," reflex operations of mind are wholly involuntary.

Although the unconscious mind plays fully as prominent a rôle in the economy of life as does the conscious mind, this treatise will not discuss the former, except indirectly. Yet, an outline sketch as to what is meant by the unconscious mind will be necessary, in order that the reader may more fully comprehend my meaning when discussing conscious mind.

A brief investigation of the anatomy, physiology, and psychology of the medusa, or jelly-fish, will serve to illustrate the operations of the unconscious mind as it is to be noticed in its reflex and "vegetative" phases. The higher and more evolved phases of the unconscious mind will not be discussed in this work, except incidentally, perhaps, as they may appear, from time to time, as my propositions are advanced, and the scheme of mental development is elaborated.

The medusa (the specimen that I take for study is a very common fresh-water individual) has a well-developed nervous system. Its transparent, translucent nectocalyx, or swimming-bell, has a central nervous system which is localized on the margin of the bell, and which forms the so-called "nerve-ring" of Romanes.[3] This nerve-ring is separated into an upper and lower nerve-ring by the "veil," an annular sheet of tissue which forms the floor of the swimming-bell, or "umbrella," and through a central opening in which the manubrium, or "handle," of the umbrella passes down and hangs below the margin of the bell.

The nerve-ring is well supplied with epithelial and ganglionic nerve-cells; their function is wholly reflex and involuntary; they preside over the pulsing or swimming movements of the nectocalyx. This pulsing is excited by stimulation, and is analogous, so far as movement is concerned, to the peristaltic action of the intestines. Situated on the margin of the bell are a number of very minute, round bodies, the so-called "eyes." These eyes are supplied with nerves, one of whose functions is volitional, as I will endeavor to show in my chapter on Conscious Determination.

The manubrium, or handle, is also the centre of a nerve-system. Nerves proceed from it and are spread out on the inner surface of the bell. These nerves preside over digestion, and are involuntary. Certain ganglia in the manubrium appear to preside over volitional effort. I have never been able, however, to locate their exact position, nor to determine their precise action. They will be discussed more fully in the next chapter.

The nervous system of the nectocalyx is exceedingly sensitive, responding with remarkable quickness to stimulation. When two or three minims of alcohol are dropped into a pint of water in which one of these creatures is swimming, the pulsing of the nectocalyx is notably increased in frequency and volume.

Romanes determined that the centres governing pulsation were located in the nerve-ring of the swimming-bell, and that each section of the nectocalyx had its individual nerve-centre.[4]

The pulsing of the nectocalyx occasions a flow of water into and out of the bell. This current brings both food and air (oxygen) to the animal, which is enabled to take these necessary life-sustainers into its system through the agency of vegetative nerve-action, a phase of the unconscious mind.

The unconscious mind made its appearance in animal life many thousands of years before the conscious mind came into existence. The latter psychical manifestation had its origin in sensual perception, which, in turn, gave rise to mental recepts and concepts.

In order fully to understand the origin of mind, it will be necessary to investigate the senses as they are observed in the lower animals. The first manifestation of conscious mind, which is, as I believe, conscious determination, or, volitional effort, is directly traceable to stimuli affecting the senses. This primal operation of conscious mind, and the manner in which it is developed from sensational perceptions, will now be discussed.