Preface to Second Edition. xv 



criticism has been given privately in letters, and notes on 

 the proof-sheets; but one of the most elaborate of his discus 

 sions of the subject was communicated to the Cambridge 

 Philosophical Society some years ago; as it was not published, 

 however, I am unfortunately unable to refer the reader to it. 

 I ought to add that he is not in any way committed to any 

 of my opinions upon the subject, from some of which in fact 

 he more or less dissents. I am also much indebted to 

 Mr J. W. L. Glaisher, also of Trinity College, for many hints 

 and references to various publications upon the subject of 

 Least Squares, and for careful criticism (given in the midst 

 of much other labour) of the chapter in which that subject is 

 treated. 



I need not add that, like every one else who has had to 

 discuss the subject of Probability during the last ten years, 

 [ have made constant use of Mr Todhunter s History. 



I may take this opportunity of adding that a considerable 

 )ortion of the tenth chapter has recently appeared in the 

 anuary number of Mind, and that the substance of several 

 chapters, especially in the more logical parts, has formed part 

 f my ordinary lectures in Cambridge; the foundation and 

 ogical treatment of Probability being now expressly included 

 n the Schedule of Subjects for the Moral Sciences Tripos. 



March, 1876. 



