Page:The Zoologist, 4th series, vol 4 (1900).djvu/145

Rh same spirit runs throughout Dr. J.E. Taylor's 'Sagacity and Morality of Plants.'

Animal intelligence has been opposed by two great factors—the philosophy of Descartes In discussing a philosophy like that of Descartes one must not trust alone to his own impressions and reading of the philosopher, or a critic may soon be found to prove that either he has not such an intimate acquaintance with the language in which it was written as to prevent misunderstanding, or that his mind is not sufficiently attuned to escape misconception. I will therefore quote some authorities to whom these objections do not, or should not, apply. According to Dr. Martineau, Descartes taught that "the soul, i.e. the thinking principle, though united with the whole body, exercises its chief functions in the brain." "But the soul he pronounced to be exclusively human, and, in the human being, a substance entirely distinct from the body." Hence animals are automata. "All the things that you make Dogs or Horses or Monkeys do are only movements of their fear, their hope, or their joy, which can be made without any thought" ('Types of Ethical Theory,' 3rd edit. vol. i. pp. 141, 144, 145).—Prof. Mahaffy, describing Descartes' opinion on the point, and in respect to the supposition that other animals, from the likeness of their organs to ours, may have some thought, though less perfect than our own, makes him, in rejoinder, to say:—"To this I have nothing to reply, except that, if they thought as we do, they must have an immortal soul, which is not likely, as we have no reason to extend it to some animals without extending it to all, such as Worms, Oysters, Sponges, &c." Thus, as Prof. Mahaffy further remarks:—"The difficulty which the opponents of Descartes felt most strongly was the possible extension of souls to Oysters and Worms. Thus theological questions determined the questions on both sides" ('Descartes,' pp. 180 and 182). It is a relief to turn to Kenan, who describes Francis of Assisi as "far removed from the brutality of the false spiritualism of the Cartesians; he only acknowledged one sort of life; he recognized degrees in the scale of being, but no sudden interruption; like the sages of India, he could not admit that false classification which places man on one side, and, on the other, those thousand forms of life of which we only see the outside, and in which, though our eyes detect only uniformity, there may lie infinite diversity. For Francis, nature had but one voice" ('Studies in Religious History,' p. 313). Even Weismann may be considered no supporter of the view of animal intelligence, judging from the following remarks:—"It is usually considered that the origin and variation of instincts are also dependent upon the exercise of certain groups of muscles and nerves during a single life-time, and that the gradual improvement which is thus caused by practice is accumulated by hereditary transmission. I believe that this is an entirely erroneous view, and I hold that all instinct is entirely due to the operation of natural selection, and has its foundation, not upon inherited experiences, but upon the variations of the germ" ('Lectures on Heredity,' &c, Eng. transl., 2nd edit. vol. i. p. 92). and theological dogma. The first