CONTENTS. vii 



PAGE 



25. Hypotheses are to be defended against Ostwald, who 

 confuses their real with their psychological value. 

 Hypotheses are indispensable means of reaching "a com- 

 plete synoptic inventory " of the Objective 71 



26. This function is well illustrated by the history of the atom. 

 Bacon recognised that the use of this concept was an 

 attempt to render some facts intelligible by means of 

 others ... ... ... ... ... ... ... ... 74 



27. But Gassendi actually reintroduced the atom into modern 



philosophy 75 



28. Kobert Boyle applied it in a genuinely scientific treatment 



of chemical facts 76 



29. Newton indicated the manner in which the concept might 

 be employed throughout the whole range ol physical 

 science... ... ... ... ... ... ... ... 78 



30. It was from Newton that John Dalton drew his inspira- 

 tion. He applied the notion of atoms of varying weight 

 first to the elucidation of a physical problem, and only 

 subsequently to the facts of chemical combination ... 78 



^31. The atom as used by Boyle and Dalton led to the precise 

 definition of two of the most important problems of 

 chemistry. With this its functions had, so far, been 

 completed, and its further use was,- strictly, unnecessary 81 



32. Objective facts are not fully determined until they have 

 been correlated with terms of the number series. The 

 attempt to do this in some cases (e.g., the hotness of 

 bodies) leads to a new concept of the "objective condi- 

 tion " of the body .-. ... 83 



33. This condition is not an Objective fact (in our sense), but 

 has " pragmatic " value only. The consideration of the 

 problems involved here leads to the completion of the 

 theory of the Thing begun in Chapter T, 6 85 



34. The early development of the science of Heat illustrates 

 the mode in which a hypothesis leads to the discovery of 

 a mathematical formula which may be regarded as an 

 expression of the fact that the elements concerned "take 

 note " of one another's condition 90 



$ 35. Failure to find such a formula leads to the discovery that 

 other elements are involved in the scheme of relations 

 under consideration 91 



36. The elements of the Objective are brought by this process 

 into some form of unity. This form may, in certain 

 cases, simulate the Objective character of the Thing ... 92 



37. Moreover, there appears to be no more than a practical 

 difficulty in the way of an inclusion of psychical elements 

 in these forms of unity :. 93 



