OF ARTS AND SCIENCES. 437 



This reasoning is logically perfect. The first premise (if I may be 

 allowed to call it so) is proved mathematically ; the second is consid- 

 ered evident, and has seldom or never been expressed by writers on 

 the subject, and the conclusion follows from the obvious principle, that, 

 when compelled to adopt one of two possible suppositions, we select the 

 most probable one. 



The most elaborate argument in favor of the first premise is that 

 given by Mr. Michell in the Philosophical Transactions for 1767. 

 Professor J. D. Forbes of Edinburgh has taken some exceptions to 

 Michell's methods, and to the general logical accuracy of his method 

 of treatment, besides pointing out one of two mathematical errors in his 

 computations,* in an article in the Philosophical Magazine for Decem- 

 ber, 1850. He raises the following objections: — 



" FiusT Objection. — The doubt existing in the mind of a reason- 

 able person whether an event still future, and ivhich may happen many 

 ways, shall occur in a particular given way, is erroneously considered 

 as equivalent to an inherent improbability of its happening or having 

 happened in that way" 



Second Objection. — To assume that every star is as likely, not 

 hypothetically, but actually, to be in one situation as another, leads to 

 conclusions obviously at variance with the idea of random or lawless 

 distribution, and is therefore not the expression of that idea. 



He also negatives the following conclusions, which he conceives must 

 be maintained by Michell's followers : — 1. That there is any calctdable 

 probability, such as 9570 to 1, against the observed occurrence of tAvo 

 stars out of more than 1000 within 4" of one another having been for- 

 tuitous. 2. That the fact of two stars being seen within an infinitely 

 small distance of each other amounts to a mathematical proof of the 

 certainty of their being physically connected. 3. That were the stars 

 uniformly spaced over the heavens, or arranged with perfect symmetry, 

 no argument could be alleged against such arrangement being the re- 

 sult of chance, but any deviation from symmetry would raise such an 

 argument. 



With regard to the first objection it may be remarked, that, except 

 the word inherent, what Professor Forbes objects to is equivalent to the 

 very mathematical definition of the word probability. It seems likely 

 that he uses the word in that sentence to express the idea or entity 



* Neither of these errors affects the general character of the result. 



