September 7, 191 1] 



NATURE 



325 



Not 1 hat these are the only great problems for the 

 biologist, nor that there is even but a single class of 

 great problems in Biology. For Bacon himself speaks 

 agnatia naturae, quoad usus humanos, the study 

 ol which has lor its objects " the prolongation of life or 

 One retardation of age, the curing of diseases counted in- 

 ,uiai>lr, the mitigation of pain, the making of new species 

 and transplanting ot one species into another," and so on 

 thrutigh many more. Assuredly 1 have no need to remind 

 you that a great feature ol this generation of ours has 

 been the way in which Biology has been justified ot her 

 fthildren, in ' the work of those who have studied the 

 magnolia naturae, quoad usus lutmanos. 



Bui so far are biologists from being nowadays engrossed 

 in practical questions, in applied and technical Zoology, to 

 the neglect of its more recondite problems, that there never 

 was a time when men thought more deeply or laboured 

 with greater zeal over the fundamental phenomena of 

 living things ; never a time when they reflected in a 

 Broad i spirit over such questions as purposive adaptation, 

 file harmonious working of the fabric of the body in 

 relation to environment, and the interplay of all the 

 creatures that people the earth ; over the problems of 

 heredity and variation ; over the mysteries of sex, and the 

 phenomena of generation and reproduction, by which 

 phenomena, as the wise woman told, or reminded, 

 Socrates, and as Harvey said again (and for that matter, 

 as Coleridge said, and Weismann, but not quite so well) — 

 by which, as the wise old woman said, we gain our glimpse 

 of insight into eternity and immortality. These, then, 

 together with the problem of the Origin of Species, are 

 indeed magnolia naturae; and I take it that inquiry into 

 these, deep and wide research specially directed to the 

 solution of these, is characteristic of the spirit of our time, 

 and is the pass-word of the younger generation of 

 biologists. 



Interwoven with this high aim which is manifested in 

 the biological work of recent years is another tendency. 

 It is the desire to bring to bear upon our science, in 

 greater measure than before, the methods and results of 

 the other sciences, both those that in the hierarchy of 

 knowledge are set above and below, and those that rank 

 alongside of out own. 



Before the great problems of which I have spoken, the 

 cleft between Zoology and Botany fades away, for the 

 same problems are common to the twin sciences. When 

 the zoologist becomes a student, not of the dead, but of 

 the living, of the vital processes of the cell rather than of 

 the dry bones of the body, he becomes once more a physio- 

 logist, and the gulf between these two disciplines dis- 

 appears. When he becomes a physiologist, he becomes, 

 1/150 facto, a student of chemistry and of physics. Even 

 mathematics has been pressed into the service of the 

 biologist, and the calculus ol probabilities is not the only 

 branch of mathematics to which he may usefully appeal. 



The physiologist has long had as his distinguishing 

 characteristic, giving his craft a rank superior to the sister 

 branch of morphology, the fact that in his great field of 

 work, and in all the routine of his experimental research, 

 the methods of the physicist and the chemist, the lessons 

 of the anatomist, and the experience of the physician are 

 inextricably blended in one common central field of investi- 

 gation and thought. But it is much more recently that 

 the morphologist and embryologist have made use of the 

 method of experiment, and of the aid of the physical and 

 chemical sciences — even of the teachings of philosophy : all 

 in order to probe into properties of the living organism 

 that men were wont to take for granted, or to regard as 

 beyond their reach, under a narrower interpretation of the 

 business of the biologist. Driesch and Loeb and Roux are 

 three among many men who have become eminent in this 

 Way in recent years, and their work we may take as typical 

 of methods and aims such as those of which I speak. 

 Driesch, both by careful experiment and by philosophic 

 insight, Loeb, by his conception of the dynamics of the 

 cell and by his marvellous demonstrations of chemical and 

 mechanical fertilisation, Roux, with his theory of auto- 

 determination, and by all the labours of the school of 

 Ent-wickelttngsmechanik which he has founded, have all in 

 various ways, and from more or less different points of 



NO. 2184, VOL. 87] 



view, helped to reconstruct and readjust our ideas of the 

 relations of embryological processes, and hence of the 

 phenomenon of life itself, on the one hand to physical 

 causes (whether external to or latent in the mechanism of 

 the cell), or on the other to the ancient conception of a 

 Vital Element alien to the province of the physicist. 



No small number of theories or hypotheses, that seemed 

 for a time to have been established on ground as firm as 

 that on which we tread, have been reopened in our day. 



I he adequacy of natural selection to explain the whole of 

 organic evolution has been assailed on many sides; the 

 old fundamental subject of embryological debate between 

 ill- evolutionists or preformationists (of the school of 

 Malpighi, llaller, and Bonnet) and the advocates of 



pigenesis (the followers of Aristotle, of Harvey, of Caspar 

 F. Wolff, and of Von Baer) is now discussed again, in 

 altered language, but as a pressing question of the hour; 

 the very foundations of the cell-theory have been scrutinised 

 to decide (for instance) whether the segmented ovum, or 

 even the complete organism, be a colony of quasi- 

 independent cells, or a living unit in which cell differentia- 

 tion is little more than a superficial phenomenon ; the 

 whole meaning, bearing, and philosophy of evolution has 

 been discussed by Bergson, on a plane to which neither 

 Darwin nor Spencer ever attained ; and the hypothesis of 

 a Vital Principle, or vital element, that had lain in the 

 background for near a hundred years, has come into men's 

 mouths as a very real and urgent question, the greatest 

 question for the biologist of all. 



In all ages the mystery of organic form, the mystery of 

 growth and reproduction, the mystery of thought and 

 consciousness, the whole mystery of the complex pheno- 

 mena of life, have seemed to the vast majority of men to 

 call for description and explanation in terms alien to the 

 language which we apply to inanimate things ; though at 

 all times there have been a few who sought, with the 

 materialism of Democritus, Lucretius, or Giordano Bruno, 

 to attribute most, or even all, of these phenomena to the 

 category of physical causation. 



For the first scientific exposition of Vitalism we must go 

 back to Aristotle, and to his doctrine of the three parts 

 of the tripartite Soul : according to which doctrine, in 

 Milton's language, created things " by gradual change 

 sublimed, To vital spirits aspire, to animal, To intel- 

 lectual ! " The first and lowest of these three, the 

 \frvxv v OpewTiicv, by whose agency nutrition is effected, is 

 7/ ttpuitv slfX')' the inseparable concomitant of Life itself. It 

 is inherent in the plant as well as in the animal, and in 

 the Linna-an aphorism, Vegetabilia crescunt et vivunt, its 

 existence is admitted in a word. Under other aspects, it 

 is all but identical with the 4>vxri at'if-nTim) and y(vr)TiKT), 

 the soul of growth and of reproduction : and in this com- 

 posite sense it is no other than Driesch 's "Entelechy," 

 the hypothetic natural agency that presides over the form 

 and formation of the body. Just as Driesch 's psychoid or 

 psychoids, which are the basis of instinctive phenomena, of 

 sensation, instinct, thought, reason, and all that directs 

 that bodv which entelechy has formed, are no other than 

 the alnOriTiKT) whereby animalia vivunt et sentiunt, and the 

 Siai'OTjTi/tVj to which Aristotle ascribes the reasoning faculty 

 of man. Save only that Driesch, like Darwin, would deny 

 the restriction of rof.v, or reasoning, to man alone, and 

 would extend it to animals, it is clear, and Driesch him- 

 self admits, 1 that he accepts both the vitalism and the 

 analysis of vitalism laid down by Aristotle. 



The -nvevna of Galen, the vis plastica, the vis vita,- 

 formatrix, of the older physiologists, the Bildungstrieb of 

 ibach, the Lebenskraft of Paracelsus, Stahl. and 

 [Yeviranus, "shaping the physical forces of the body to 

 its own ends," "dreaming dimly in the grain of the 

 promise of the full corn in the ear," 3 these and many 

 more, like Driesch's " entelechy " of to-day, are all con- 

 ceptions under which successive generations strive to depict 



1 "Science and Philosophy of the Organism" (Gifford [Lectures), ii. 



Jenlcinson (Art. "Vitalism" in llil-ho-t !.-:,r,:al, Apr.l, ioti) 

 who has given me the following quotation: "Pas Weitzenkorn hat 

 allerdinss BewusMsein dessen was in ihm i^t und aus ihm werden kann, und 

 traiimt wirklich davon. Sein Bewusstsein und sunt Traume mogen dunkel 

 genus sein"; Treviranus, "Erscheinungen und Gesetze des organischen 

 Lebens, 8^1. 



