LAW OF CAUSATION. 893 



objects retires, and leaves them dead and inactive. Instead of 

 moving voluntarily, we find them to be moved necessarily ; 

 instead of acting, we find them to be acted upon ; and Nature 

 appears as one great machine, where one wheel is turned by 

 another, that by a third ; and how far this necessary succes 

 sion may reach, the philosopher does not know.&quot;* 



There is, then, a spontaneous tendency of the intellect to 

 account to itself for all cases of causation by assimilating them 

 to the intentional acts of voluntary agents like itself. This is 

 the instinctive philosophy of the human mind in its earliest 

 stage, before it has become familiar with any other invariable 

 sequences than those between its own volitions or those of other 

 human beings and their voluntary acts. As the notion of fixed 

 laws of succession .among external phenomena gradually 

 establishes itself, the propensity to refer all phenomena to volun 

 tary agency slowly gives way before it. The suggestions, how 

 ever, of daily life continuing to be more powerful than those of 

 scientific thought, the original instinctive philosophy maintains 

 its ground in the mind, underneath the growths obtained by 

 cultivation, and keeps up a constant resistance to their throw 

 ing their roots deep into the soil. The theory against which 

 I am contending derives its nourishment from that substratum. 

 Its strength does not lie in argument, but in its affinity to an 

 obstinate tendency of the infancy of the human mind. . 



That this tendency, however, is not the result of an in 

 herent mental law, is proved by superabundant evidence. 

 The history of science, from its earliest dawn, shows that 

 mankind have not been unanimous in thinking either that the 

 action of matter upon matter was not conceivable, or that the 

 action of mind upon matter was. To some thinkers, and 

 some schools of thinkers, both in ancient and in modern times, 

 this last has appeared much more inconceivable than the 

 former. Sequences entirely physical and material, as soon as 

 they had become sufficiently familiar to the human mind, came 

 to be thought perfectly natural, and were regarded not only as 

 needing no explanation themselves, but as being capable of 



* Reid s Essays on the Active Powers, Essay iv. ch. 3. 



