Thus we see that it seems necessary to draw a marked distinction between two types of calculability. Calculation based on insight into individual character and purpose is so far from being inconsistent with purposiveness and intelligence, that the more coherent and systematic the purposes by which a life is controlled, the more confident does such calculation become. Calculation without such special knowledge, and based upon mere general propositions, on the other hand, cannot be regularly successful where one has to deal with the behaviour of individual purposive beings.[129] Now, the difficulty as to our interpretation of the physical order as the presentation to our sense of a system of intelligent purposive beings, is that the successes of physical science seem at first sight to show that just this “mechanical” calculation of the course of events from observed sequence, without insight into underlying individual purpose, _is_ possible when we are dealing with physical nature. For, on the one hand, we ourselves admitted that if physical nature is permeated by individual purposes, we do not know what those purposes in detail are; and, on the other, it is undeniable that physical science, which systematically disregards their presence, has been signally successful in the past, and may be expected to be even more successful in the future, in detecting uniformities in physical nature, and so submitting it to exact calculation. Hence it might be thought that the actual success of the empirical sciences cannot be reconciled with the principles of our metaphysical interpretation of the course of nature.