LAW, CAUSE 369 



another, and no attention is paid to the spatial or temporal 

 locations of the events concerned. This is accomplished, in 

 the case of temporal laws, by inserting the value giving 

 the temporal duration into the equation as one of the inde- 

 pendent variables; instead of saying that a certain value of 

 y is followed by a certain value of x it states that a certain 

 value of y is a function of a certain value of x and a certain 

 value of t — the value of /, of course, being properly expressible 

 as (ti — to) since it represents a duration, i.e., the difference 

 between two clock times. Similar considerations apply to 

 laws of coexistence, in so far as they involve spatial intervals. 

 The reduction of laws of succession to this purely logical 

 form is more important since these laws " allow us to predict 

 in advance a certain course of events; much less frequently 

 do we need those which allow us to conclude from a state 

 of affairs at one point or another, what is happening simul- 

 taneously elsewhere. But in principle, these two cases of 

 'dynamic' and 'static' causality, as we might call them, 

 have no priority one over the other. The essential feature, 

 the conclusion from a determined A to a co-determined B, 

 is in both cases exactly the same, only that in one case time 

 occurs among the necessary variables, and not in the other 

 case." 1 Hence one may say that the difference between 

 laws of coexistence and laws of succession lies not in the 

 character of the functional relation itself, but in the charac- 

 ter of the variables which are thus related; the former con- 

 tain no time variable while the latter do. 



But the matter cannot be dismissed too lightly, for it is 

 tied up with the question of causal laws in science. Many 

 believe, for example, that whatever may be said as to the 

 existence of causal connections at the empirical level nothing 

 of the kind is required for science. There are in science no 

 causal laws if one means by these certain unique types of 

 correlation differing from functional relations. For there 

 are only two respects in which such laws could differ from 

 the more general types of mathematical correlation — in 



1 B. Bavink, The Natural Sciences, p. 75. 



