History of the Conflict Between Religion and Science

by John William Draper

Such a duration of impressions on the retina proves that the effect of external influences on nerve-vesicles is not necessarily transitory. In this there is a correspondence to the duration, the emergence, the extinction, of impressions on photographic preparations. Thus, I have seen landscapes and architectural views taken in Mexico developed, as artists say, months subsequently in New York—the images coming out, after the long voyage, in all their proper forms and in all their proper contrast of light and shade. The photograph had forgotten nothing. It had equally preserved the contour of the everlasting mountains and the passing smoke of a bandit-fire.

Are there, then, contained in the brain more permanently, as in the retina more transiently, the vestiges of impressions that have been gathered by the sensory organs? Is this the explanation of memory—the Mind contemplating such pictures of past things and events as have been committed to her custody. In her silent galleries are there hung micrographs of the living and the dead, of scenes that we have visited, of incidents in which we have borne a part? Are these abiding impressions mere signal-marks, like the letters of a book, which impart ideas to the mind? or are they actual picture-images, inconceivably smaller than those made for us by artists, in which, by the aid of a microscope, we can see, in a space not bigger than a pinhole, a whole family group at a glance?

The phantom images of the retina are not perceptible in the light of the day. Those that exist in the sensorium in like manner do not attract our attention so long as the sensory organs are in vigorous operation, and occupied in bringing new impressions in. But, when those organs become weary or dull, or when we experience hours of great anxiety, or are in twilight reveries, or are asleep, the latent apparitions have their vividness increased by the contrast, and obtrude themselves on the mind. For the same reason they occupy us in the delirium of fevers, and doubtless also in the solemn moments of death. During a third part of our life, in sleep, we are withdrawn from external influences; hearing and sight and the other senses are inactive, but the never-sleeping Mind, that pensive, that veiled enchantress, in her mysterious retirement, looks over the ambrotypes she has collected—ambrotypes, for they are truly unfading impressions—and, combining them together, as they chance to occur, constructs from them the panorama of a dream.

Nature has thus implanted in the organization of every man means which impressively suggest to him the immortality of the soul and a future life. Even the benighted savage thus sees in his visions the fading forms of landscapes, which are, perhaps, connected with some of his most pleasant recollections; and what other conclusion can be possibly extract from those unreal pictures than that they are the foreshadowings of another land beyond that in which his lot is cast? At intervals he is visited in his dreams by the resemblances of those whom he has loved or hated while they were alive; and these manifestations are to him incontrovertible proofs of the existence and immortality of the soul. In our most refined social conditions we are never able to shake off the impressions of these occurrences, and are perpetually drawing from them the same conclusions that our uncivilized ancestors did. Our more elevated condition of life in no respect relieves us from the inevitable operation of our own organization, any more than it relieves us from infirmities and disease. In these respects, all over the globe men are on an equality. Savage or civilized, we carry within us a mechanism which presents us with mementoes of the most solemn facts with which we can be concerned. It wants only moments of repose or sickness, when the influence of external things is diminished, to come into full play, and these are precisely the moments when we are best prepared for the truths it is going to suggest. That mechanism is no respecter of persons. It neither permits the haughtiest to be free from the monitions, nor leaves the humblest without the consolation of a knowledge of another life. Open to no opportunities of being tampered with by the designing or interested, requiring no extraneous human agency for its effect, out always present with every man wherever he may go, it marvelously extracts from vestiges of the impressions of the past overwhelming proofs of the realities of the future, and, gathering its power from what would seem to be a most unlikely source, it insensibly leads us, no matter who or where we may be, to a profound belief in the immortal and imperishable, from phantoms which have scarcely made their appearance before they are ready to vanish away.

The insect differs from a mere automaton in this, that it is influenced by old, by registered impressions. In the higher forms of animated life that registration becomes more and more complete, memory becomes more perfect. There is not any necessary resemblance between an external form and its ganglionic impression, any more than there is between the words of a message delivered in a telegraphic office and the signals which the telegraph may give to the distant station; any more than there is between the letters of a printed page and the acts or scenes they describe, but the letters call up with clearness to the mind of the reader the events and scenes.

An animal without any apparatus for the retention of impressions must be a pure automaton—it cannot have memory. From insignificant and uncertain beginnings, such an apparatus is gradually evolved, and, as its development advances, the intellectual capacity increases. In man, this retention or registration reaches perfection; he guides, himself by past as well as by present impressions; he is influenced by experience; his conduct is determined by reason.

A most important advance is made when the capability is acquired by any animal of imparting a knowledge of the impressions stored up in its own nerve-centres to another of the same kind. This marks the extension of individual into social life, and indeed is essential thereto. In the higher insects it is accomplished by antennal contacts, in man by speech. Humanity, in its earlier, its savage stages, was limited to this: the knowledge of one person could be transmitted to another by conversation. The acts and thoughts of one generation could be imparted to another, and influence its acts and thoughts.

But tradition has its limit. The faculty of speech makes society possible—nothing more.

Not without interest do we remark the progress of development of this function. The invention of the art of writing gave extension and durability to the registration or record of impressions. These, which had hitherto been stored up in the brain of one man, might now be imparted to the whole human race, and be made to endure forever. Civilization became possible—for civilization cannot exist without writing, or the means of record in some shape.

From this psychological point of view we perceive the real significance of the invention of printing—a development of writing which, by increasing the rapidity of the diffusion of ideas, and insuring their permanence, tends to promote civilization and to unify the human race.