§ 45. Such proficiency as science affords is in every case the anticipation of experience. This has a twofold value for mankind, that of _accommodation_, and that of _construction_. Primitively, where mere survival is the function of the organism as a whole, the value of accommodation is relatively fundamental. The knowledge of what may be expected enables the organism to save itself by means of its own counter-arrangement of natural processes. Construction is here for the sake of accommodation. But with the growth of civilization construction becomes a positive interest, and man tends to save himself for definite ends. Accommodation comes to take place for the sake of construction. Science then supplies the individual with the ways and means wherewith to execute life purposes which themselves tend to assume an absolute value that cannot be justified merely on the ground of science. [Sidenote: Method and Fundamental Conceptions of Natural Science. The Descriptive Method.] § 46. If natural science be animated by any special cognitive interest, this motive should appear in the development of its method and fundamental conceptions. If that interest has been truly defined, it should now enable us to understand the progressive and permanent in scientific investigation as directly related to it. For the aim of any discipline exercises a gradual selection from among possible methods, and gives to its laws their determinate and final form. The _descriptive method_ is at the present day fully established. A leading moral of the history of science is the superior usefulness of an exact account of the workings of nature to an explanation in terms of some qualitative potency. Explanation has been postponed by enlightened science until after a more careful observation of actual processes shall have been made; and at length it has been admitted that there is no need of any explanation but perfect description. Now the practical use of science defined above, requires no knowledge beyond the actual order of events. For such a purpose sufficient reason signifies only sufficient conditions. All other considerations are irrelevant, and it is proper to ignore them. Such has actually been the fate of the so-called metaphysical solution of special problems of nature. The case of Kepler is the classic instance. This great scientist supplemented his laws of planetary motion with the following speculation concerning the agencies at work: "We must suppose one of two things: either that the moving spirits, in proportion as they are more removed from the sun, are more feeble; or that there is one moving spirit in the centre of all the orbits, namely, in the sun, which urges each body the more vehemently in proportion as it is nearer; but in more distant spaces languishes in consequence of the remoteness and attenuation of its virtue."[129:2] The following passage from Hegel affords an interesting analogy: