18 



scientific questions respecting human nature which are still 

 in abeyance. It is yet undecided whether our thoughts, 

 emotions, and volitions are generated through the intervention 

 of material mechanism; whether we have organs of thought 

 and of emotion in the same sense in which we have organs of 

 sensation. Many eminent physiologists hold the affirmative. 

 These contend that a thought (for example) is as much the 

 result of nervous agency as a sensation; that some particular 

 state of the nervous system, in particular of that central 

 portion of it called the brain, invariably precedes, and is pre- 

 supposed by every state of our consciousness. According to 

 this theory, one state of mind is never really produced by 

 another; all are produced b^ states of body. When one 

 thought seems to call up another by association, it is not really 

 a thought which recalls a thought ; the association did not exist 

 between the two thoughts, but between the two states of the 

 brain or nerves which preceded the thought ; one of those states 

 recalls the other, each being attended in its passage by the 

 particular mental state which is consequent upon it. On this 

 theory, the uniformities of succession among states of mind 

 would be mere derivative uniformities, resulting from the laws 

 of succession of the bodily states which cause them." 1 



While maintaining that the facts of mind must be studied 

 independently of their antecedent physiological facts, Mill, 

 in further commenting on this matter, states: "The relations, 

 indeed, of that science to the science of physiology must never 

 be overlooked or undervalued. It must by no means be for- 

 gotten that the laws of mind may be derivative laws, resulting 

 from laws of animal life, and that their truth may therefore 

 ultimately depend upon physical conditions; and the influence 

 of physiological states or physiological changes in altering or 

 counteracting the mental successions, is one of the most im- 

 portant departments of psychological study." 2 



With very little change, then, the mechanical theory, so 

 explicitly stated by Hartley, is handed down from the elder to 

 the younger Mill. Though perhaps more implicit in the latter, 

 the essential bearing is practically the same. The significance 

 of the theory within the sphere of Ethics may be seen in 

 Mill's statement that all human character is the product of 

 circumstances, formed "through the universal principle of 

 association". 3 



'O.C. VI, 4, 2. 



2 Ibid. 



3 J. S. Mill, "An Autobiography", p. 108. 



