372 Insurance and Gambling. [CHAP, xv, 



take fire so readily, or precautions may be taken that there 

 shall be fire-engines at hand. In the warding off of death 

 from disease and accident, something may be done by every 

 one who chooses to live prudently. Precautions of the above 

 kind, however, do not introduce any questions of Probability. 

 These latter considerations only come in when we begin to 

 invoke the regularity of the average to save us from the 

 irregularities of the details. We cannot, it is true, remove 

 the uncertainty in itself, but we can so act that the conse 

 quences of that uncertainty shall be less to us, or to those in 

 whom we are interested. Take the case of Life Insurance. 

 A professional man who has nothing but the income he earns 

 to depend upon, knows that the whole of that income may 

 vanish in a moment by his death. This is a state of things 

 which he cannot prevent; and if he were the only one in 

 such a position, or were unable or unwilling to combine with 

 his fellow-men, there would be nothing more to be done in 

 the matter except to live within his income as much as pos 

 sible, and so leave a margin of savings. 



3. There is however an easy mode of escape for him. 

 All that he has to do is to agree with a number of others, 

 who are in the same position as himself, to make up, so to 

 say, a common purse. They may resolve that those of their 

 number who live to work beyond the average length of life 

 shall contribute to support the families of those who die 

 earlier. If a few only concurred in such a resolution they 

 would not gain very much, for they would still be removed 

 by but a slight step from that uncertainty which they are 

 seeking to escape. What is essential is that a considerable 

 number should thus combine so as to get the benefit of that 

 comparative regularity which the average, as is well known, 

 almost always tends to exhibit. 



4. The above simple considerations really contain the 



