qualities. Galilei, writing as early as 1623 in II Saggiatore, a 

 polemical work on astronomy, makes the claim that the sensa- 

 tions of taste, smell, colour, etc. are not, as have been formerly 

 held, qualities of things but that they have their seat in the sensi- 

 tive body. An object is called red not because it itself is red but 

 because it excites that sensation in us, that is, in the physiological 

 organism. On the other hand, however, there are certain first 

 and real qualities (primi e reali accidenti), which are inseparable 

 from things. These are figure, magnitude and motion or rest. 

 By these qualities of things, that is by motions in space, Galilei 

 thought to explain all other qualities. In his famous Dialogue he 

 clearly expresses the view that it is only possible to understand 

 the qualitative changes in nature when these can be traced back 

 to quantitative changes. Now such a view, implying that there is 

 an objective, absolute and realistic space, in which occur certain 

 movements which give rise to sensations, lies at the root of nearly 

 all the mechanical views of nature that have been advanced since 

 the time of Galilei. Gassendi, in his writings, and Newton, in his 

 Principia and Opticks, held essentially this same theory in regard 

 to space, while, in recent times, physical science, with but few 

 exceptions, presupposes an absolute space which it claims to be 

 independently real. 



But this theory of space has been dominant not only in physical 

 science; its influence is also to be clearly seen in philosophical circles. 

 The mechanistic and materialistic world-views, which have been 

 advanced from time to time, rest upon this assumption in regard 

 to space, and the fact that the same theory of space has been held 

 so generally in the special sciences has often helped to validate 

 in the eyes of many these incorrect and inadequate philosophical 

 theories. 



If one turns to the centuries immediately preceding the work 

 of Kant, he finds that these views in regard to space were preva- 

 lent in nearly all of the philosophical writings of that time. Hobbes 

 held that "a body is that, which having no dependence upon our 

 thought, is coincident or coextended with some part of space". 1 

 Space, that is for Hobbes, real space and not imaginary space, 

 for he distinguishes these two, is a characteristic common to all 



1 De Corpora, Ch. VIII, Par. 1. 



97 



