LAW OF CAUSATION. 383 



7. It continually happens that several different phe 

 nomena, which are not in the slightest degree dependent or 

 conditional on one another, are found all to depend, as the 

 phrase is, on one and the same agent; in other words, one 

 and the same phenomenon is seen to be followed by several 

 sorts of effects quite heterogeneous, but which go on simul 

 taneously one with another; provided, of course, that all other 

 conditions requisite for each of them also exist. Thus, the sun 

 produces the celestial motions, it produces daylight, and it 

 produces heat. The earth causes the fall of heavy bodies, and 

 it also, in its capacity of a great magnet, causes the pheno 

 mena of the magnetic needle. A crystal of galena causes 

 the sensations of hardness, of weight, of cubical form, of grey 

 colour, and many others between which we can trace no inter 

 dependence. The purpose to which the phraseology of Pro 

 perties and Powers is specially adapted, is the expression of 

 this sort of cases. When the same phenomenon is followed 

 (either subject or not to the presence of other conditions) by 

 effects of different and dissimilar orders, it is usual to say that 

 each different sort of effect is produced by a different property 

 of the cause. Thus we distinguish the attractive or gravita- 

 tive property of the earth, and its magnetic property : the 

 gravitative, luminiferous, and calorific properties of the sun : 

 the colour, shape, weight, and hardness of a crystal. These 

 are mere phrases, which explain nothing, and add nothing to 

 our knowledge of the subject ; but, considered as abstract 

 names denoting the connexion between the different effects 

 produced and the object which produces them, they are a very 

 powerful instrument of abridgment, and of that acceleration of 

 the process of thought which abridgment accomplishes. 



This class of considerations leads to a conception which we 

 shall find to be of great importance, that of a Permanent 

 Cause, or original natural agent There exist in nature a 

 number of permanent causes, which have subsisted ever since 

 the human race has been in existence, and for an indefinite 

 and probably an enormous length of time previous. The sun, 

 the earth, and planets, with their various constituents, air, 

 water, and other distinguishable substances, whether simple or 



