20 THE POPULAR SCIENCE MONTHLY, 



these substances that translate the identical excitation of all the 

 nerves into sense-perceptions, each set, according to its own nature, 

 acting as carriers of Joh. Muller's " specific energies," and so giving 

 quality. The Mosaic dictum, " There was light," is j)hysiologically 

 false. Light first was when the first red eye-point of an infusorial ani- 

 mal for the first time distinguished light from darkness. In the absence 

 of the sense-substance of sight and hearing, this bright, glowing, reso- 

 nant world around us would be dark and voiceless. 



And voiceless and dark in itself, i. e., property-less, as the uni- 

 verse is on subjective decomposition of the phenomena of sense, so is 

 it also from the mechanical stand-point, gained by objective contem- 

 plation. Here, in place of sound and light, we have only the vibrations 

 of a primitive, undifferentiated matter, which here has become pon- 

 derable, and there imponderable. 



But, however well grounded these views may be in general, noth- 

 ing, as we may say, has been done toward carrying them out in detail. 

 The philosoj^her's stone that should transmute into one another the as 

 yet unanalyzed elements, and produce them from a higher element, if 

 not from primeval matter itself, must be discovered before the first 

 conjecture as to the development of apparently heterogeneous, from 

 actually homogeneous matter, becomes possible. 



Though the human mind will ever remain very remote from the 

 mind imagined by Laplace, yet this is only a matter of degree, in 

 some measure like the difference between a given ordinate of a curve 

 and another immeasurably greater, though still finite, ordinate of the 

 same curve. We resemble this mind, inasmuch as we conceive of it. 

 We might even ask whether a mind like that of ISTewton does not dif- 

 fer less from the mind imagined by Laplace, than the mind of an Aus- 

 tralian or of a Fuegian savage differs from the mind of Newton. In 

 other words, the impossibility of stating and integrating the differen- 

 tial equations of the universal formula, and of discussing the result, is 

 not fundamental, but rests on the impossibility of getting at the ne- 

 cessary determining facts, and, even where this is possible, of master- 

 ing their boundless extension, multiplicity, and complexity. 



Thus the knowledge of Nature possessed by the mind imagined by 

 Laplace, represents the highest thinkable grade of our own natural 

 science. Hence we may lay this down as the basis of our inquiry as 

 to the limits of this science. Whatever would remain unknown to 

 such a mind, must be perfectly hidden away from our minds, which are 

 confined within much narrower bounds. 



There are two positions where even the mind imagined by La23lace 

 would strive in vain to press on farther, and where we have to stand 

 stock-still. 



In the first place we must observe that the knowledge of Nature 

 already spoken of as provisionally satisfying our desire of tracing 

 things to their causes, in reality does no such thing, and is not 



