Dr. WHEWELL'S SECOND MEMOIR, ETC. 615 



for the fact. But in the writings of Archimedes we find this fact brought within the domain 

 of necessary truth. It was there transferred from the empirical to the ideal side of the Fundamental 

 Antithesis ; and thus a progressive step was made in science. In like manner, it was at fir.st taken 

 by Galileo as a mere fact of experience, that in a falling body, the velocity increases in proportion 

 to the time ; but his followers have seen in this the necessary effect of the uniform force of gravity. 

 In like manner, Kepler's empirical Laws were shewn by Newton to be necessary results of a central 

 force attracting inversely as the square of the distance. And if it be doubtful whether this is 

 the necessary law of a central force, as some philosophers have maintained that it is, we cannot 

 doubt that if those philosophers could establish their doctrine as certain, they would make an 

 important step in science, in addition to those already made. 



And thus, such steps in science are made, whenever empirical facts are discerned to be neces- 

 sary laws; or, if I may be allowed to use a briefer expression, whenever /ac<s are idealized. 



Sn. In order to shew how widely this statement is applicable, I will exemplify it in some of 

 the other sciences. 



In Chemistry, not to speak of earlier steps in the science, which might be presented as instances 

 of the same general process, we may remark that the analyses of various compounds into their 

 elements, according to the quantity of the elements, form a vast multitude of facts, which were 

 previously empirical only, but which are reduced to a law, and therefore to a certain kind of ideal 

 necessity, by the discovery of their being compounded according to definite and multiple propor- 

 tions. And again, this very law of definite proportions, which may at first be taken as a law given 

 by experience only, it has been attempted to make into a necessary truth, by asserting that bodies 

 must necessarily consist in atoms, and atoms must necessarily combine in definite small numbers. 

 And however doubtful this Atomic Theory may at ))resent be, it will not be questioned that any 

 chemical philosopher who could establish it, or any other Theory which would produce an equiva- 

 lent change in the aspect of the science, would make a great scientific advance. And thus, in this 

 Science also, the Progress of Science consists in the transfer of facts from the empirical to the neces- 

 sary side of the antithesis; or, as it was before expressed, in the idealization of facts. 



37. We may illustrate the same process in the Natural History Sciences. The discovery of 

 the principle of Morphology in plants, was the reduction of a vast mass of Facts to an Idea ; as 

 Schiller said to Gothe when he explained the discovery ; although the latter, cherishing a horrour 

 of the term Idea, which perhaps is quite as common in England as in Germany, was extremely 

 vexed at being told that he possessed such furniture in his mind. The applications of this Principle 

 to special cases, for instance, to Euphorbia by Brown, to Reseda by Lindley, have been attempts to 

 idealize the facts of these special cases. 



38. We may apply the same view to steps in Science which are still under discussion ; — the 

 question being, whether an advance has really been made in science or not. For instance, in Astro- 

 nomy, the Nebular Hypotliesis has been propounded, as an explanation of many of tlie observed 

 phenomena of the Universe. If this Hypothesis could be conceived ever to be established as a true 

 Tiieory, this must be done by its taking into itself, as necessary parts of the whole Idea, many 

 Facts which have already been observed ; such as the various form of nebuhx ; many Facts whicli 

 it must require a long course of years to observe, such as the changes of nebulte from one form to 

 anolhcr ; and many facts which, so far as we can at present judge, are utterly at variance with the 

 Idea, such as the motions of satellites, the relations of the elements of planets, the existence of vege- 

 table and animal life upon their surfaces. But if all these Facts, when fully studied, sliould appear 

 to be included in the general Idea of Nebular Condensation according to the Laws of Nature, the 

 Facts so idealized would undoubtedly constitute a very rcmarkal)le advance in science. But then, 

 we are to recollect that we are not to suppose that the I'acts will agree with the Idea, merely 

 because the Idea, considered by itself, and without carefully attending to the Facts, is a large and 

 striking Idea. And we are also to recollect that the Facts may l)e compared with another Idea, no 



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