14 THE AIM AND ACHIEVEMENTS OF SCIENTIFIC METHOD. 



qualities are not isolated reals, each one wearing the qualities it 

 v^ owns without regard to any other. Eather do they all form 

 part of one spatial real, " the physical order," which includes 

 our own bodies. Then it may be said in general that the 

 qualities perceived to exist in any one part of the real are 

 correlated with those perceivable in other parts including that 

 part (or " body ") with which the perceiving " centre " has a 

 special connection. Whether the same part of the physical real 

 will be perceived as occupied by the same quality at the same 

 time by two " centres of experience " or by the same centre at 

 different times cannot be decided in any given case by a priori 

 reasoning. Thus the colours seen in the same surface by 

 daylight and gaslight are different, while the sounds heard from 

 the same bell would not perceptibly change with the change 

 of light. If a bell is sounded near different observers the sound 

 heard will depend upon the velocities with regard to the air of 

 the bell and the percipient's body, and it seems probable that it 

 will depend only upon these velocities, so that if these are 

 identical in the case of two observers, identical sounds will be 

 heard. In the case of the hotness or coldness felt in a 

 particular part of the real (for example, a basin of water), the 

 quality perceived to exist depends upon other conditions which 

 involve the percipient's body in what may be called an internal 

 way. It is clear that this account may be extended to include 

 such extreme cases as " colour-blindness," or complete absence 

 of certain forms of sensibility. The all-important point is that 

 \ve cannot deny to the qualities perceived the Objectivity, the 

 " priority " to our perception that they claim to have in each 

 case; scientific "explanations" of the phenomena consisting 

 largely, I repeat, in bringing to light .other Objective facts 

 which exist as well as the primary facts from which the 

 explanations start, and in no sense exist instead of these.* 



* I need hardly point out how much I am indebted to Mr. G. E. Moore 

 in this discussion. Mr. Moore dealt with the subject in a paper read before 

 the Aristotelian Society in December, 1905 some months after, under his 



