But the most comprehensive view may be the most distorted and false. The true order of knowledge is the difficult task of logical analysis, requiring as its chief essential some determination of the scope of the working conceptions of the different independent branches of knowledge. In the case of natural science this would mean an examination of the method and results characteristic of this field, for the sake of defining the kind of truth which attaches to the laws which are being gradually formulated. But one must immediately reach either the one or the other of two very general conclusions. If the laws of natural science cover all possible knowledge of reality, then there is left to philosophy only the logical function of justifying this statement. Logic and natural science will then constitute the sum of knowledge. If, on the other hand, it be found that the aim of natural science is such as to exclude certain aspects of reality, then philosophy will not be restricted to logical criticism, but will have a cognitive field of its own. The great majority of philosophers have assumed the latter of these alternatives to be true, while most aggressive scientists have intended the former in their somewhat blind attacks upon "metaphysics." Although the selection of either of these alternatives involves us in the defence of a specific answer to a philosophical question, the issue is inevitable in any introduction to philosophy because of its bearing upon the extent of the field of that study. Furthermore there can be no better exposition of the meaning of philosophy of science than an illustration of its exercise. The following, then, is to be regarded as on the one hand a tentative refutation of _positivism_, or the _claim of natural science to be coextensive with knowable reality_; and on the other hand a programme for the procedure of philosophy with reference to natural science. [Sidenote: The Origin of the Scientific Interest.] § 42. Science issues through imperceptible stages from organic habits and instincts which signify the possession by living creatures of a power to meet the environment on its own terms. Every organism possesses such a working knowledge of nature, and among men the first science consists in those habitual adjustments common to men and infra-human organisms. Man is already practising science before he recognizes it. As _skill_ it distinguishes itself early in his history from lore, or untested tradition. Skill is familiarity with general kinds of events, together with ability to identify an individual with reference to a kind, and so be prepared for the outcome. Thus man is inwardly prepared for the alternation of day and night, and the periods of the seasons. He practically anticipates the procession of natural events in the countless emergencies of his daily life. But science in the stricter sense begins when skill becomes _free_ and _social_. [Sidenote: Skill as Free.]