The wonders of life : a popular study of biological philosophy / by Ernst Haeckel ; translated by Joseph McCabe.
- Ernst Haeckel
- Date:
- 1905
Licence: In copyright
Credit: The wonders of life : a popular study of biological philosophy / by Ernst Haeckel ; translated by Joseph McCabe. Source: Wellcome Collection.
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![and birds on the one hand, and of mammals on the other, show us how the higher psychic powers have been developed step by step from the lower. To this physio- logical scale corresponds exactly the mor- phological gradation revealed by the com- parative anatomy of the brain. The most interesting and important part of this is that which relates to the highest developed class—the mammals ; within this class we find the same ever-advancing gradation. At its summit are the primates (man, the apes, and the half-apes), then the carnivora, a part of the ungulates, and the other placentals. A wide interval seems to separate these intelligent mammals from the lower placentals, the marsupials and monotremes. We do not find in the latter the high quantitative and qualitative development of the phronema which we have in the former; yet we find every intermediate stage between the two. The gradual development of the cerebrum and its chief part—the phronema—took place during the Tertiary period, the duration of which is estimated by many recent geo- logists at from twelve to fifteen (at the least three to five) million years. A.S I have gone somewhat fully, in chapters vi.-ix. of the Riddle, into the chief results of the modern study of the brain and its radical importance for psychology and the theory of knowledge, I need only refer the reader thereto. There is just one point I may touch here, as it has been attacked with particular vehemence by my critics. I had made several allusions to the works of the distinguished English zoologist, Romanes, who had made a careful comparative study of mental development in the animal and man, and had continued the work of Darwin. Romanes partly retracted his monistic convictions shortly before his death, and adopted mystic religious views. As this conversion was known at first only through one of his friends, a zealous English theo- logian [Dr. Gore], it was natural to retain a certain reserve. However, it turned out that there had really been in this case (just as in the case of the aged Baer) one of those interesting psychological metamor- phoses which I have described in chapter vi. of the Riddle. Romanes suffered a good deal from illness and grief at the loss of friends in his last years. In this condition of extreme depression and melancholy he fell under mystic influences which promised him rest and hope by belief in the super- natural. It is hardly necessary to point out to impartial readers that such a con- version as this does not shake his earlier monistic views. As in similar cases where deep emotional disturbance, painful experi- ences, and exuberant hope have clouded the judgment, we must still hold that it is the place of the latter, and not of the emotions or of any supernatural revelation, to attain a knowledge of the truth. But for such attainment it is necessary for the organ of mind, the phronema, to be in a normal condition.' Of all the wonders of life, consciousness may be said to be the greatest and most astounding. It is true that to-day most physiologists are agreed that man’s con- sciousness, like all his other mental powers, is a function of the brain, and may be reduced to physical and chemical processes in the cells of the cortex. Nevertheless, some biologists still cling to the meta- physical view that this “ central mystery of psychology” is an insoluble enigma, and not a natural phenomenon. In face of this, I must refer the reader to the monistic theory of consciousness which I have given in chapter x. of the Riddle, and must insist that in this case again embryology is the best guide to a comprehension of the sub- ject. Sight is next to consciousness, in many respects, as one of the wonders of life. The well-known embryology of the eye teaches us how sight—the perception of images from the external world—has been gradually evolved from the simple sensitiveness to light of the lower animals, by the development of a transparent lens. In the same way the conscious soul, the internal mirror of the mind’s own action, has been produced as a new wonder of life out of the unconscious associations in the phronema of ourearliervertebrateancestors. In diametrical opposition to our monistic and empirical theory of knowledge, the prevailing dualistic metaphysics assumes that our knowledge is only partly empirical and d posteriori, and is partly quite inde- pendent of experience and d priori, or due to the original constitution of our “ im- material” mind. The powerful authority of Kant has lent enormous prestige to this mystic and supernatural view, and the academic philosophers of our time are endeavouring to maintain it. A “return ' English readers who are acquainted with Romanes’s posthumous Thoughts ott Religion will recognise the justice of this analysis. Romanes speaks expressly of the acceptance of Christianity entailing “ the sacrifice of his intel- lect.”—Trans.](https://iiif.wellcomecollection.org/image/b28075754_0027.jp2/full/800%2C/0/default.jpg)
