C 375 3 
Mr. Bayes has thought fit to begin his work with 
a brief demonftration of the general laws of chance. 
His reafon for doing this, as he fays in his introduc- 
tion, was not merely that his reader might not have 
the trouble of fearching elfewhere for the principles 
on which he has argued, but becaufe he did not know 
whither to refer him for a clear demonflration or 
them. He has alfo made an apology for the peculiar 
definition he has given of the word chance or proba- 
bility. His defign herein was to cut off all difpute 
about the meaning of the word, which in common 
language is ufed in different fenfes by perfons of dif- 
ferent opinions, and according as it is applied to pajl 
or future faCts. But whatever different fenfes it may 
have, all (he obferves) will allow that an expectation 
depending on the truth of any pajl faCt, or the hap- 
pening of any future event, ought to be eflimated fo 
much the more valuable as the fa Ct is more likely to 
be true, or the event more likely to happen. Inflead 
therefore, of the proper fenfe of the word probabi- 
lity , , he has given that which all will allow to be its 
proper meafure in every cafe where the word is ufed. 
But it is time to conclude this letter. Experimental 
philofophy is indebted to you for feveral difcoveries 
and improvements ; and, therefore, I cannot help 
thinking that there is a peculiar propriety in direct- 
ing to you the following effay and appendix. That 
your enquiries may be rewarded with many further 
fucceffes, and that you may enjoy every every valuable 
bleffing, is the fincere wifh of, Sir, 
your very humble fervant, 
Richard Price. 
N ewington- G reen , 
Nov. xo, 1763. 
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