PREFACE. 



The favourable reception which has been granted to my History 

 of the Calculus of Variations daring the Xineteenth Century has 

 encouraged me to undertake another work of the same kind. 

 The subject to which I now invite attention has high claims to 

 consideration on account of the subtle problems which it involves, 

 the valuable contributions to analysis which it has produced, its 

 important practical applications, and the eminence of those who 

 have cultivated it. 



The nature of the problems which the Tlieory of Probability 

 contemplates, and the influence which this Theory has exercised 

 on the progress of mathematical science and also on the concerns 

 of practical life, cannot be discussed within the limits of a Preface ; 

 we may however claim for our subject all the interest wdiicli illus- 

 trious names can confer, by the simple statement that nearly 

 every gi-eat mathematician within the range of a century and a 

 half will come before us in the course of the history. To mention 

 only the most distinguished in this distinguished roll — we sliall 

 find here — Pascal and Format, worthy to be associated by kindred 

 genius and character— De Moivre with his rare powers of analysis, 

 which seem to belong only to a later epoch, and which justify the 

 honour in which he was held by Newton — Leibnitz and the emi- 

 nent school of which he may be considered the founder, a school 

 including the Bernoullis and Euler — D'Alembert, one of the most 

 conspicuous of those who brought on the French revolution, and 

 Condorcet, one of the most illustrious of its victims — Lagrange 

 and Laplace who survived until the present century, and may be 

 regarded as rivals at that time for the suj^remacy of the mathe- 

 matical world. 



I will now give an outline of the contents of the book. 



The first Chapter contains an account of some anticipations 

 of the subject which are contained in the writings of Cardan, 

 Kepler and Galileo. 



The second Chapter introduces the Chevalier de Mere' who 

 having puzzled himself in vain over a problem in chances, 

 fortunately turned for help to Pascal : the Problem of Points is 

 discussed in the correspondence between Pascal and Format, and 

 thus the Theory of Probability begins its career. 



