52 INTRODUCTION TO PHILOSOPHY OF SCIENCE 



While Russell's distinction is of basic importance in the 

 understanding of cognition, it requires reinterpret at ion and 

 supplementation to be made adequate to the scientific 

 situation. In the first place something must be said with 

 reference to the directness which characterizes knowledge 

 by acquaintance. The presumption is that in acquaintance 

 one knows events directly, without the intermediary of 

 anything which is symbolic in its nature, and by this means 

 one avoids the difficulty of the common sense position which, 

 as we shall see later, considers mind to be limited to its own 

 contents. What is the nature of this directness, and what is 

 the nature of the event which is thus known ? Since the 

 detailed solution requires a consideration of the complicated 

 problem of the theory of knowledge, what is suggested here 

 may be taken for a mere outline, to be partially filled in by 

 the discussion of Chapter V. By the directness of knowing, 

 one means only the basic fact that in all cognition there 

 must be a situation which one can describe by the sentence : 

 "I am now aware of such-and-such." The presumption in a 

 situation of this kind is that the "I" is directly in contact 

 with the "such-and-such' in the sense that the latter is 

 known without any intermediary. The fact of direct acquaint- 

 ance does not prohibit the use of instrumental techniques 

 and measuring devices. It demands only that recording 

 machines be recognized for what they are, and not as sub- 

 stitutes for the observer. A registering instrument must be 

 read before it can affect knowledge, hence it is the instru- 

 ment itself which is directly known, though it may convey 

 inferential knowledge as to something else whose character 

 it is registering. One must be directly acquainted with 

 pointer readings if he is to be indirectly aware of that which 

 they measure. Even if one supposes that his sense organs 

 are recording devices, giving him information as to an ex- 

 ternal world, still he must suppose that he is immediately 

 aware of the sense-data though he may be only inferentially 

 aware of their causes. 



In the second place, it seems important to recognize that 



