SCIENCE. 



are phenomena, we cannot think them the phenomena of 

 nothing, but must regard them as the properties or quali- 

 ties of something that is extended, figured, etc. But this 

 something, absolutely and in itself — i. e., considered apart 

 from its phenomena — is to us as Zero. It is only in its 

 qualities, only in its effects, in its relative or phenomenal 

 existence, that it is cognizable or conceivable ; and it is 

 only by a law of thought which compels us to think some- 

 thing absolute and unknown, as the basis or condition 

 of the relative and known, that this something obtains a 

 kind of incomprehensible reality to us." The argument 

 here is that because phenomena are and must be the " prop- 

 erties or qualities of something else," therefore we are 

 " compelled to think " of that something as having an ex- 

 istence separable from any relation to its own qualities and 

 properties, and that this something acquires from this 

 reasoning a "kind of incomprehensible reality!" There 

 is no such law of thought. There is no such necessity of 

 thinking nonsense as is here alleged. All that we are com- 

 pelled to think is that the ultimate constitution of Matter, 

 and the ultimate source of its relations to our own organism, 

 are unknown, and are probably inaccessible to us. But 

 this is a very different conception from that which affirms 

 that if we did know or could know these ultimate truths, 

 we should find in them anything standing absolutely alone 

 and unrelated to other existences in the Universe. 



It is, however, so important that we should define to 

 ourselves as clearly as we can the nature of the limitations 

 which affect our knowledge, and the real inferences which 

 are to be derived from the consciousness we have of them, 

 that it maybe well to examine these dicta of metaphysicians 

 in the light of specific instances. It becomes all the more 

 important to do so, when we observe that the language in 

 which these dicta are expressed generally implies that 

 knowledge which is " only relative " is less genuine or less 

 absolutely true than some other kind of knowledge which 

 is not explained, except that it must be knowledge of that 

 which has no relation to the mind. 



There is a sense (and it is the only sense in which the 

 words have any meaning) in which we are all accustomed 

 to ssy that we know a thing " in itself," when we have 

 found out, for example, its origin, or its structure, or its 

 chemical composition as distinguished from its more sup- 

 erficial aspects. If a new substance were offered to us as 

 food, and if we examined its appearance to the eye, and 

 felt its consistency to the touch, and smelt its odor, and 

 finally tasted it, we should then know as much about it as 

 these various senses could tell us. Other senses, or other 

 forms of sensation, might soon add their own several con- 

 tributions to our knowledge, and we might discover that 

 this substance had deleterious effects upon the human or- 

 ganism. This would be knowing, perhaps, by far the most 

 important things that are to be known about it. But we 

 should certainly like to know more, and we should prob- 

 ably consider that we had found out what it was "in itself," 

 when we had discovered farther, for example, that it was 

 the fruit of a tree. Chemistry might next inform us of the 

 analysis of the fruit, and might exhibit some alkaloid to 

 which its peculiar properties and its peculiar effects upon 

 the body are due. This, again, we should certainly con- 

 sider as knowing what it is "in itself." But other que stions 

 respecting it would remain behind. How the tree can ex- 

 tract this alkaloid from the inorganic elements of the soil, 

 and how, when so extracted, it should have such and such 

 peculiar effects upon the animal body ; these, and similar 

 questions, we may ask, and probably we shall ask in vain. 

 But there is nothing in theinaccessibility of this knowledge 

 to suggest that we are absolutely incapable of understand- 

 ing the answer if it were explained to us. On the contraiy, 

 the disposition we have to put such questions raises a 

 strong presumption that the answer would be one capable 

 of that assimilation by our intellectual nature in which all 

 understanding of anything consists. There is nothing in 

 the series of phenomena which this substance has exhibited 

 to us — nothing in the question which they raise which can 

 even suggest the idea that all these relations which we have 

 traced, or any others which may remain behind, are the re- 

 sult of something which can be thought of or conceived as 

 neither a cause nor a consequence — but solitary and unre- 

 lated. On the contrary, all that remains unexplained is 

 the nature and cause of its relations — its relations on the 



one hand to the elements out of which vegetable vitality 

 has combined it, and its relations on the other hand to the 

 still higher vitality which it threatens to destroy. Its place 

 in the unity of Nature is the ultimate object of our search, 

 and this unity is essentially a unit}' of relations, and of 

 nothing else. That unity everywhere proclaims the truth 

 that there is nothing in the wide universe which is unre- 

 lated to the rest. 



Let us take another example. Until modern science had 

 established its methods of physical investigation, Light and 

 Sound were known as sensations only. That is to say, they 

 were known in terms of the mental impressions which they 

 immediately produce upon us, and in no other terms what- 

 ever. There was no proof that in these sensations we had 

 any knowledge " in themselves " of the external agencies 

 which produce them. But now all this is changed. Science 

 has discovered what these two agencies are "in themselves ;" 

 - — that is to say, it has defined them under aspects which are 

 totally distinct from seeing or hearing, and is able to de- 

 scribe them in terms addressed to wholly different faculties 

 of conception. Both Light and Sound are in the nature of 

 undulatory movements in elastic media — to which undula- 

 tions our organs of sight and hearing are respectively ad- 

 justed or "attuned." In these organs, by virtue of that 

 adjustment or attuning, these same undulations are "trans- 

 lated " into the sensations which we know. It thus appears 

 that the facts as described to us in this language of sensation 

 are the true equivalent of the facts as described in the very 

 different language of intellectual analysis. The eye is now 

 understood to be an apparatus for enabling the mind instan- 

 taneously to appreciate differences of motion which are of al- 

 most inconceivable minuteness. The pleasure we derive from 

 the harmonies of color and of sound, although mere sensa- 

 tions, do correctly represent the movement of undulations in 

 a definite order; whilst those other sensations which we know 

 as discords represent the actual clashing and disorder of in- 

 terfering waves. In breathing the healthy air of physical 

 discoveries such as these, although the limitations of our 

 knowledge continually haunt us, we gain nevertheless a tri- 

 umphant sense of its certainty and of its truth. Not only 

 are the mental impressions, which our organs have been so 

 constructed as to convey, a true interpretation of external 

 facts, that the conclusions we draw as to their origin and 

 their source, and as to the guarantee we have for the accu- 

 racy of our conceptions, are placed on the firmest of all 

 foundations. The mirror into which we look is a true mir- 

 ror, reflecting accurately and with infinite fineness the reali- 

 ties of Nature, And this great lesson is being repeated in 

 every new discovery, and in every new application of an old 

 one. Every reduction of phenomena to ascertained meas- 

 ures of force ; every application of mathematical proof to 

 theoretical conceptions ; every detection of identical opera- 

 tions in diverse departments of Nature ; every subjection of 

 material agencies to the service of mankind ; every confir- 

 mation of knowledge acquired through one sense by the 

 evidence of another — every one of these operations adds to 

 the verifications of science, confirms our reasonable trust 

 in the faculties we possess and assures us that the knowl- 

 edge we acquire by the careful use of these is a real and 

 substantial knowledge of the truth. 



If now we examine the kind of knowledge respecting 

 Light and Sound which recent discoveries have revealed to 

 us, as compared with the knowledge which we had of them 

 before these discoveries were made, we shall find out that 

 there is an important difference. The knowledge which we 

 had before was the simple and elementary knowledge of 

 sensation. As compared with that knowledge, the new 

 knowledge we have acquired respecting light and sound, is 

 a knowledge of these things " in themselves." Such is the 

 language in which we should naturally express our sense of 

 that difference, and in so expressing it we should be ex- 

 pressing an important truth. The newer knowledge is a 

 higher knowledge than the older and simpler knowledge 

 which we had before. And why? Wherein dees this 

 higher quality of the new knowledge consist ? Is it not in 

 the very fact that the new knowledge is the perception of a 

 higher kind of relation than that which we had perceived 

 before ? There is no difference between the two kinds of 

 knowledge in respect to the mere abstract character of re- 

 lativity. The old was as relative as the new ; and the new 

 is as relative as the old. Before the new discoveries sound 



