368 METHODOLOGY OF SCIENCE 



it offers is really sufficient to enable us to deduce the causal relation. 

 For this purpose let us remind ourselves that the question at issue 

 is, whether or not this relation is merely a temporal connection of 

 events that are given to us in perception or that can be derived from 

 the data of perception. 



Besides, let us grant that this relation is as thoroughly valid for 

 the content of our experience as empiricism has always, and ration- 

 alism nearly always, maintained. We presuppose, therefore, as 

 granted, that every event is to be regarded as cause, and hence, in 

 the opposite time relation, as effect, mental events that are given 

 to us in self perception no less than the physical whose source is our 

 sense perception. In other words, we assume that the totality of 

 events in our possible experience presents a closed system of causal 

 series, that is, that every member within each of the contemporary 

 series is connected with the subsequent ones, as well as with the 

 subsequent members of all the other series, backward and forward 

 as cause and effect; and therefore, finally, that every member of 

 every series stands in causal relationship with every member of 

 every other series. We do not then, for the present purpose, burden 

 ourselves with the hypothesis which was touched upon above, that 

 this connection is to be thought of as a continuous one, namely, that 

 other members can be inserted ad infinitum between any two mem- 

 bers of the series. 



We maintain at the same time that there is no justification for 

 separating from one another the concepts, causality and interaction. 

 This separation is only to be justified through the metaphysical 

 hypothesis that reality consists in a multitude of independently 

 existing substances inherently subject to change, and that their 

 mutual interconnection is conditioned by a common dependence 

 upon a first infinite cause. 1 Every connection between cause and 

 effect is mutual, if we assume with Newton that to every action 

 there is an equal opposing reaction. 



In that we bring the totality of knowable reality, as far as it is 

 analyzable into events, under the causal relation, we may regard 

 the statement that every event requires us to seek among uniformly 

 preceding events for the sufficient causes of its own reality, namely, 

 the general causal law, as the principle of all material sciences. For 

 all individual instances of conformity to law which we can discover 

 in the course of experience are from this point of view only special 

 cases of the general universal conformity to law which we have just 

 formulated. 



1 This doctrine began in the theological evolution of the Christian concept of 

 God. It was first fundamentally formulated by Leibnitz. It is retained in Kant's 

 doctrine of the harmonia generaliter stabilita and the latter 's consequences for the 

 critical doctrine of the mundus intelligibilis. Hence it permeates the metaphysical 

 doctrines of the systems of the nineteenth century in various ways. 



