Oct. 25, 18 77 J 



NA TURE 



561 



following the finite strictly and incessantly, but stopping here 

 and there in the midst of it and changing it for the eternal. 



It would lead me far indeed, if I were to consider the conse- 

 quences singly, which have arisen from thewant of a correct method 

 based upon principles. The most remarkable ones, which at the 

 same time claim a general interest, are the opinions, that finite 

 nature is divided into two radically different domains, and particu- 

 larly that there is an insuperable limit between inorganic and 

 organic, or between material and spiritual nature. I will speak 

 only of the latter opinion. 



The antagonists of an intimate connection between material 

 and immaterial nature draw the line of separation in difterent 

 places. In the opinion of some, living nature generally (or " life- 

 endowed " {bcsciUe) nature, inasmuch as life is also ascribed to 

 plants) represents something absolutely special, while others admit 

 this only for the animal world endowed with sensation, and yet 

 others only for the spiritually conscious human race ; new im- 

 material or eternal principles are said to apply to the higher 

 grades. Du Bois Reymond holds the second of these views ; he 

 says that in the first trace of pleasure which was felt by one of 

 the simplest beings in the beginning of animal life upon our 

 earth, an insuperable limit was marked, while upwards from this 

 to the most elevated mental activity, and downwards from the 

 vital force of the organic to the simple physical force he nowhere 

 finds another limit. 



It is difficult for the naturalist to oppose the supposition of 

 immaterial principles, which are said to arise suddenly here and 

 there in nature, as it places itself at once upon a stand-point 

 which lloats in the air outside of natural science, and cannot, 

 therefore, be attacked directly and contradicted l>y him. 

 Natural science can only show that this supposition is super- 

 fluous, because everj'thing can be explained in a natural way, 

 and also improbable, because otherwise a contradiction is 

 introduced into finite nature which gainsays the whole of our 

 experience, and olTends our mental desire to find causal relations 

 everywhere. 



Experience shows that from the clearest consciousness of the 

 thinker downwards, through the more imperfect consciousness of 

 the child, to the unconsciousness of the embryo, and to the 

 insensibility of the human ovum, or through the more imperfect 

 consciousness of undeveloped human races and of higher 

 animals to the unconsciousness of lower animals, and of sensitive 

 plants, and to the insensibility of all other plants, there exists a 

 continuous gradation without definable limit, and that the same 

 gradation continues from the life of the animal ovum and the 

 vegetable cell downwards through organised elementary and 

 more or less lifeless forms (parts of the cell) to crystals and 

 chemical molecules. 



But the conclusion we draw by analogy is this : — ^Just as all 

 organisms consist of and have been formed of matter, which 

 occurs in inorganic nature, so the forces, which are inherent in 

 matter, have of course entered into the formations as well. If 

 matter combines with other matter, then their forces unite to 

 some total result, and this represents the new property of the 

 resulting body ; this property is of course only relative. Thus 

 vermilion is mercury + oxygen — heat; sugar is carbon 

 ■y hydrogen + oxygen - heat. And thus life and feeling are 

 new relative properties which albumen molecules obtain under 

 certain circumstances. Accordingly, experience shows that 

 spiritual life is everywhere connected in the most intimate manner 

 with natural life, that the one influences the other and cannot 

 exist without the other. It is necessary, therefore, as every- 

 where in nature forces and motions are united only with material 

 particles, that the spiritual forces and motions also appertain to 

 matter, in other words, that they are composed of tlie general 

 forces and motions of nature and are connected with them as 

 cause and effect. No naturalist can avoid the conception of a 

 causal connection of this nature, unless he becomes unfaithful, 

 consciously or unconsciously, to his first principle. The problem 

 is, therefore, to understand how the forces of inorganic matter 

 combine in matter which forms into organisms, so that their 

 result represents life, sensation, and consciousness. The solution 

 of this problem is yet very remote ; but it is possible. We may 

 give sufficient indications for each single point. 



Permit me to speak more minutely of one of these points ; I 

 mean the one in which my predecessor sees a limit to natural 

 knowledge. This is all the more tempting since for the rest Du 

 Bois Reymond places himself upon the basis of the causal prin- 

 ciple, if indeed not in words quite so direct, yet quite as deter- 

 mined and unconditional ; and since if this one gap were filled, 

 no other would exist for his point of view. To him the whole 



world-history, even the whole system of the universe, is the con- 

 sequence of the mechanics of atoms. There is no action of the 

 mind, which could not be calculated from the forces and the 

 motions of matter, if it were possible to know these. The 

 material occurrences which are connected with the solution of 

 an arithmetical problem, with the pleasure of musical sensation, 

 with the intellectual pleasure over a scientific discovery, are pro- 

 ducts of cerebral mechanics. The mind can indeed be looked 

 upon as the secretion of the substance of the brain, in the same 

 way as gall is the secretion of the liver, as Karl Vogt, and 

 previously Cabanis, have said. 



Du Bois Reymond declares all this to be intelligible in prin- 

 ciple ; but, he says, we learn to know only the conditions of 

 mental life, but not how from these conditions ment.il life results. 

 Sensation and consciousness doubtless accompany the material 

 processes in the brain by necessity, but they stand outside of the 

 causal law and remain eternal enigmas to us. 



It is not uninteresting to follow Du Bois Reymond's view, 

 which I have just stated and which he details and illustrates 

 with various examples, into its consequences, and to consider 

 clearly its general result. We then arrive at this : — The finite 

 mind, as it has developed itself through the animal world up to 

 man, is a double one ; on the one side the acting, inventing, 

 unconscious, material mind, which puts the muscles into motion 

 and determines the world's history ; this is nothing else but the 

 mechanics of atoms, and is subject to the causal law ; and on the 

 other side the inactive, contemplative, remembering, fancying, 

 conscious, immatcnal mind, which feels pleasure and pain, love 

 and hate ; this one lies outside of the mechanics of matter and 

 cares nothing for cause and effect. 



Generally both sides of mental life are collectively called mind. 

 Du Bois Reymond exclusively designates the latter as mind, and 

 if the separation existed in the way described this would certainly 

 be the truly unintelligible secretion of the material mind, or of 

 the atoms of the brain ; it would not be anything but the useless 

 ornament of this material mind. Its infallibly following, unreal 

 shadow. Because it stands outside of the chain of cause and 

 effect, it is powerless and without influence upon actions ; with- 

 out it the world's history would have run exactly the same course 

 as it did. Also without consciousness mathematical formulas 

 would have been invented, written down, taught, and applied, 

 telegraphs and steam engines would have been constructed ; also 

 without consciousness theological and philosophical discussions 

 would have been held, printed, read, and their authors burnt at 

 the stake ; also without conscious memory lessons would have 

 been leamt by heart in the schools and examinations held ; also , 

 without musical sentiment music would have been composed, 

 repeated at rehearsals, performed and listened to with all external 

 signs of pleasure or disapprobation ; also without poetical or 

 artistic sentiment poets, painters, and sculptors would have pro- 

 duced their works, and the<e would have been admired and 

 criticised. Therefore without a conscious and perci^ived mental 

 life, we should have thought, done, and spoken everything, but 

 only mechanically, and not otherwise than a very artistically- 

 invented dead automaton would think, act, and speak. 



We cannot deny the sublimity of this conception of the uni- 

 verse ; the impression it makes upon the naturalist must be all 

 the greater, because it proceeds consequentially everywhere and 

 does not offend any natural scientific principle ; as to the imma- 

 terial and the unintelligible it assigns a domain, which lies out- 

 side of the connection of natural and real things. "For this reason 

 also this conception cannot be discussed from a natural scientific 

 point of view. And yet to the naturalist certain objections 

 present themselves. 



Can we imagine that so many occurrences, which most evi- 

 dently resulted from sensation and consciousness, have some 

 other sensationless and unconscious origin ? Can we imagine that 

 sensation and consciousness are so entirely useless, and while 

 everywhere utility {zwcckmiissigkcit) is so eminently prominent in 

 organic nature, that so useless and superfluous a phenomenon 

 should occur just where we expect the greatest utility ? Can we 

 imagine that the causal principle, which governs the whole of 

 nature, fails us just at the most important part ? Can we imagine 

 that organised matter accidentally and without cause acquires a 

 property (sensation and consciousness), and loses it again acci- 

 dentally and without effect, because in the ovum and in the 

 embryo the conscious and perceived mental life would not be 

 present, it would arise gradually, it would 'oe lost in sleep every 

 night, obtained again more or less completely in the waking statej 

 and annihilated for ever in death ? 



The conscience of the naturalist is little satisfied by this new 



