DISCOVERT OF COINCIDENCES. 445 



tant circumstances of that effect ; and any condition, ex- 

 cept a preventive one, may be a concomitant circumstance. 

 All the properties of a body, and many of the effects of 

 those properties, must always co-exist with the body, and 

 be present in all static and dynamic phenomena in which 

 the body itself is present or takes a part, and therefore 

 form either necessary or mere coincident circumstances in 

 all such phenomena. Also in any case where one force pro- 

 duces two or more effects in a single substance, or where 

 two or more forces are inseparable and act together, coin- 

 cidences are likely to occur. For instance, as the influ- 

 ence of gravity is always acting throughout all space, and 

 cannot be excluded, its effects must be coincident with 

 those of all other forces in every instance. The effects of 

 magnetism and of an electric current are also frequently 

 coincident, because the latter force cannot exist without 

 the former accompanying it. 



In consequence of the number of forms of energy con- 

 tinually operating; and of the action of a single force 

 only upon a single substance producing simultaneously 

 many effects ; l and in consequence also of the almost infi- 

 nite number of phenomena continually occurring through- 

 out all space, many phenomena must exist at the same 

 moment in the same space, or in close conjunction and 

 contiguity; and coincident circumstances must be ex- 

 tremely abundant, and single isolated ones excessively 

 rare. Kemarkable events must also sometimes happen 

 together, independent of all real connection. 



Coincident circumstances may be divided into sepa- 

 rable and inseparable. The former are usually called for- 

 tuitous or accidental circumstances, and are often the 

 result of independent chains of causes ; for instance, the 

 collision or non-collision of two ships at sea during dark- 



1 See Chapter IV., pp. 32, 33. 



