§ 1. The popular conception of the physical order as exhibiting a rigid mechanical conformity to general _laws_, conflicts with our metaphysical interpretation. § 2. Our interpretation would, however, admit of the establishment of averages or approximately realised uniformities by the statistical method, which deals with occurrence _en bloc_ to the neglect of their individual detail. § 3. “Uniformity” in nature is neither an axiom nor an empirically verifiable fact, but a postulate. A consideration of the methods actually employed for the establishment of such uniformities or “laws” of nature shows that we have no guarantee that actual concrete cases exhibit _exact_ conformity to law. § 4. Uniformity is a _postulate_ arising from our need of practical rules for the control of nature. It need not for this purpose be exact, and in point of fact our scientific formulæ are only exact so long as they remain abstract and hypothetical. They do not enable us to determine the actual course of an individual process with certainty. § 5. The concept of the physical order as _mechanical_ is the abstract expression of the postulate, and is therefore essential to the empirical sciences which deal with the physical order. § 6. Consideration of the character of genuine machines suggests that the mechanical only exists as a subordinate aspect of processes which, in their full nature, are intelligent and purposive 216 CHAPTER IV SPACE AND TIME