350 INTRODUCTION TO PHILOSOPHY OF SCIENCE 



durations. On the other are theoretical laws which are ex- 

 pressed as functional relations between variables. The latter 

 type of law is strictly scientific, and an analysis of it will be 

 made in the proper place. The question at issue is whether 

 the tables of values (or the plottings of them on coordinate 

 schemes) constitute laws at the strictly empirical level. The 

 question is not important since, as has already been seen, 

 there are many levels of the empirically given. Throughout 

 the discussion thus far the point of view has been taken that 

 the recognition of precise quantitative features of the given 

 involves the beginnings of the transition to the scientific 

 point of view. At the lowest of the empirical levels, though 

 quantitative differences are obscurely recognized, measure- 

 ment techniques have not yet been employed; hence at this 

 level a law states merely the fact of presence or absence, with 

 little or no awareness of the possibility of degrees of presence 

 or absence. For this reason a table of measured values, 

 though it is often called an empirical law, will be considered 

 from the point of view of this discussion as a rudimentary 

 scientific formulation. 



(2) The structure of correlations is the structure of space 

 and time, hence the types of laws will be determined by the 

 types of spatio-temporal relations. Events occur at the same 

 or at different times, and they may exist at the same or at 

 different spatial locations. This fact determines two general 

 types of laws: laws of coexistence and laws of succession, 

 each of which may describe the correlation of events which 

 occupy the same space or different spaces. If the world were 

 a perfect system, and if one's knowledge of its laws were 

 complete, then from a knowledge of an event here and now 

 one could determine by means of laws of coexistence what is 

 happening now everywhere, and by means of laws of succes- 

 sion what will happen and what has happened. Such a state 

 of affairs is not at all apparent on the empirical level, how- 

 ever. All that seems to be given is the clustering of events 

 into spatial groups and into historical continuities; the 

 persistence of this associative character leads to the formula- 



