PRESIDENTIAL ADliRl':.SS — SKCTK'M I'. 127 



spring^s from an intrinsic feature of immediate experience, 

 namely, its endless variety and particularity, and the correspond- 

 ing complexity of its conditions. The sense-impressions of each 

 indixidual are in all cases and at all times different from those of 

 every other. Even when we are looking- at the same thing, for 

 example, the sight sensations of each of us are diff'erent. The 

 appearances of things differ with our point of view, with our 

 bodily organization and mental outfit, with the sensitiveness of 

 our sense-organs, etc. A thing is seen as of a different colour 

 according as it is reflected on the centre or the margin of the 

 retina, with the light in which it is seen, the state of the atmos- 

 phere, etc. A note in a chord sounds differently than when heard 

 alone ; and so on endlessly. Moreover, the s])ace sensations of 

 sight, of touch, and of hearing, even of the same individual at 

 the same time, are different spaces. So it is with the time sensa- 

 tions of each of us. But habitual exijerience leads us to co- 

 ordinate these different spaces and times, and through mutual 

 action and response we come to interpret the conditions of our 

 sense-impressions as consisting of a world that is common to 

 all of us and as lying in the relations between the things that 

 constitute this common world. It is here that science takes 

 its rise. 



In order to describe the relations between things in a way 

 that is independent of any particular kind of sense-impression 

 or the sense-impressions of any particular individual, science 

 abstracts from all such diff'erences. and seeks to state in general 

 terms — " in a neutral universal fashion " — the nature of the 

 reality determining our experiences. Starting from the funda- 

 mental experience of change of sense-impression, along Avith 

 that of the togetherness or grouping of impressions — that is, 

 from experiences of time and space — science interprets the con- 

 ditions of changes in our sense-impressions as consisting in 

 changes of position, i.e., motion in things. For science, there- 

 fore, the various characters of our sense-impressions — the 

 several sense-qualities — are our mode of apprehending changes 

 o^f position or motions on the part of things or the elements of 

 things. Colours, sounds, pressures, odours, temperatures, etc., 

 are our way of appreciating such changes according to their kind 

 or degree. For the purpose of stating the conditions of ex- 

 perience, i.e., of saying precisely what conditions will have such 

 or such consequences in the way of experience, science resolves 

 these into configurations of molecules, motions of ether, wave- 

 forms, or the like ; duration into a single onward-flowing time ; 

 and extension into a vast space in which things exist and events 

 or changes in things occur. But as experienced colour is visual 

 sensation, sound is auditory sensation, extension, shape, size, 

 position, even motion itself, consist in modes or relations of 

 tactual, visual, and muscular sensations. Similarly, such con- 

 ceptions as force, resistance, weight, body, are one and all, in 

 the first instance, actual sensations or sets of sensations. Force, 

 for example, definable as any condition or determinant of motion, 



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