have urged that such a method should not be summoned to questions in mental philosophy. To do so, say they, is to confound things distinct, requiring distinct plans of study. Such a criticism might have had weight in the days when the mind was supposed to inhabit the body as a tenant a house, and have no relation to it other than that of a casual occupant. But that opinion is antiquated. More than three-fourths of a century ago the far-seeing thinker, Wilhelm von Humboldt, laid down the maxim that the phenomena of mind and matter obey laws identical in kind;6–1 and a recent historian of science sums up the result of the latest research in these words:
“The old dualism of mind and body, which for centuries struggled in vain for reconciliation, finds it now, not indeed in the unity of substance, but in the unity of laws.”6–2
It is, therefore, as a question in mental philosophy to be treated by the methods of natural science, that I shall approach the discussion of the religious sentiment. As it is a part, or at least a manifestation of mind, I must preface its more particular consideration with some words on the mind in general, words which I shall make as few and as clear as possible.
At the beginning of this century, the naturalist Oken hazarded the assertion: “The human mind is a memberment of infusorial sensation,”7–1 a phrase which has been the guiding principle of scientific psychology ever since. That in the course of this memberment or growth wholly new faculties are acquired, is conceded. As the union of two inorganic substances may yield a third different in every respect from either; or, as in the transition of inorganic to organic matter, the power of reproduction is attained; so, positively new powers may attend the development of mind. From sensations it progresses to emotions, from emotions to reason. The one is the psychical climax of the other. “We have still to do with the one mind,whose action developes itself with perception, through discrimination, till it arrives at notions, wherein its most general scheme, ‘truth and error,’ serves as the principle.”8–1
Extravagant as Oken’s expression seemed to many when it was published, it now falls short of the legitimate demands of science, and I may add, of religion. Mind is co-extensive with organism; in the language of logic, one “connotes” the other; this statement, and nothing short of it, satisfies the conditions of the problem. Wherever we see Form preserved amid the change of substance, there is mind; it alone can work that miracle; only it gives Life. Matter suffers no increase; therefore the new is but a redistribution of the old; it is new in form only; and the maintenance of form under changes of substance is the one distinguishing mark of organism. To it is added the yet more wonderful power of transmitting form by reproduction. Wherever these are, are also the rudiments of mind. The distinction between the animal and the vegetable worlds, between the reasoning and unreasoning animals, is one of degree only. Whether, in a somewhat different sense, we should not go yet further, and say that mind is co-extensive with motion, and hence with phenomena, is a speculative inquiry which may have to be answered in the affirmative, but it does not concern us here.
The first and most general mark of Mind is sensation or common feeling. In technical language a sensation is defined to be the result of an impression on an organism, producing some molecular change in its nerve or life centres. It is the consequence of a contact with another existence. Measured by its effects upon the individual the common law of sensation is: Every impression, however slight, either adds to or takes from the sum of the life-force of the system; in the former case it produces a pleasurable, in the latter a painful sensation. The exceptions to this rule, though many, are such in appearance only.9–1
In the human race the impression can often be made quite as forcibly by a thought as by an act. “I am confident,” says John Hunter, the anatomist, “that I can fix my attention to any part, until I have a sensation in that part.” This is what is called the influence of the mind upon the body. Its extent is much greater than used to be imagined, and it has been a fertile source of religious delusions. Such sensations are called subjective; those produced by external force, objective.
The immediate consequent of a sensation is reflex action, the object of which is either to avoid pain or increase pleasure, in other words, either to preserve or augment the individual life.
The molecular changes incident to a sensation leave permanent traces, which are the physical bases of memory. One or several such remembered sensations, evoked by a present sensation, combine with it to form an Emotion. Characteristic of their origin is it that the emotions fall naturally into a dual classification, in which the one involves pleasurable or elevating, the other painful or depressing conditions. Thus we have the pairs joy and grief, hope and fear, love and hate, etc.
The question of pleasure and pain is thus seen to be the primary one of mental science. We must look to it to explain the meaning of sensation as a common quality of organism. What is the significance of pleasure and pain?
The question involves that of Life. Not to stray into foreign topics, it may broadly be said that as all change resolves itself into motion, and, as Helmholtz remarks, all science merges itself into mechanics, we should commence by asking what vital motions these sensations stand for or correspond to.
Every organism, and each of its parts, is the resultant of innumerable motions, a composition of forces. As such, each obeys the first law of motion, to wit, indefinite continuance of action until interfered with. This is a modification of Newton’s “law of continuance,” which, with the other primary laws of motion, must be taken as the foundation of biology as well as of astronomy.11–1
The diminution or dispersion of organic motion is expressed in physiological terms as waste; we are admonished of waste by pain; and thus admonished we supply the waste or avoid the injury as far as we can. But this connection of pain with waste is not a necessary one, nor is it the work of a Providentia particularis, as the schoolmen said. It is a simple result of natural selection. Many organisms have been born, no doubt, in which waste did not cause pain; caused, perhaps, pleasure. Consequently, they indulged their preferences and soon perished. Only those lived to propagate their kind in whom a different sensation was associated with waste, and they transmitted this sensitiveness increased by ancestral impression to their offspring. The curses of the human race to-day are alcohol, opium and tobacco, and they are so because they cause waste, but do not immediately produce painful but rather pleasurable feelings.
Pain, as the sensation of waste, is the precursor of death, of the part or system. By parity of evolution, pleasure came to be the sensation of continuance, of uninterrupted action, of increasing vigor and life. Every action, however, is accompanied by waste, and hence every pleasure developes pain. But it is all important to note that the latter is the mental correlative not of the action but of its cessation, not of the life of the part but of its ceasing to live. Pain, it is true, in certain limits excites to action; but it is by awakening the self-preservative tendencies, which are the real actors. This physiological distinction, capable of illustration from sensitive vegetable as well as the lowest animal organisms, has had an intimate connection with religious theories. The problems of suffering and death are precisely the ones which all religions set forth to solve in theory and in practice. Their creeds and myths are based on what they make of pain. The theory of Buddhism, which now has more followers than any other faith, is founded on four axioms, which are called “the four excellent truths.” The first and fundamental one is: “Pain is inseparable from existence.” This is the principle of all pessimism, ancient and modern. Schopenhauer, an out-and-out pessimist, lays down the allied maxim, “All pleasure is negative, that is, it consists in getting rid of a want or pain,”13–1 a principle expressed before his time in the saying “the highest pleasure is the relief from pain.”
Consistently with this, Buddhism holds out as