SECT. 21.] Fallacies. 353 



if, in other words, we keep on trying long enough, we shall 

 meet with such an event at last. If we toss up a pair of 

 dice a few times we shall get doublets ; if we try longer with 

 three we shall get triplets, and so on. However unusual the 

 event may be, even were it sixes a thousand times running, 

 it will come some time or other if we have only patience and 

 vitality enough. Now apply this result to the letters of the 

 alphabet. Suppose that one letter at a time is drawn from 

 a bag which contains them all, and is then replaced. If the 

 letters were written down one after another as they occurred, 

 it would commonly be expected that they would be found to 

 make mere nonsense, and would never arrange themselves 

 into the words of any language known to men. No more 

 they would in general, but it is a commonly accepted result 

 of the theory, and one which we may assume the reader to 

 be ready to admit without further discussion, that, if the 

 process were continued long enough, words making sense 

 would appear; nay more, that any book we chose to men 

 tion, Milton s Paradise Lost or the plays of Shakespeare, 

 for example, would be produced in this way at last. It 

 would take more days than we have space in this volume to 

 represent in figures, to make tolerably certain of obtaining 

 the former of these works by thus drawing letters out of a 

 bag, but the desired result would be obtained at length 1 . 



1 The process of calculation may combinations is favourable, if we 



be readily indicated. There are, say, reject variations of spelling. Hence 



about 350,000 letters in the work in unity divided by this number would 



question. Since any of the 26 letters represent the chance of getting the 



of the alphabet may be drawn each desired result by successive random 



time, the possible number of com- selection of the required number of 



binations would be 26 350 000 ; a num- 350,000 letters. 



ber which, as may easily be inferred If this chance is thought too small, 



from a table of logarithms, would and any one asks how often the 



demand for its expression nearly above random selection must be re- 



500,000 figures. Only one of these peated in order to give him odds of 2 



v. 23 



