372 SIR WILLIAM Hamilton's philosophy. 



altogether unexplained. It may be impossible, indeed, definitely to 

 state the estential property by which the class of phenomena, forming 

 the objects of a science, are distinguished from all others. Life in 

 general, physical as well as mental, is so many-sided, that it seems to 

 elude all our efforts to fit its Tarious phenomena into a single defini- 

 tion ; and even if we accept consciousness as the distinctive quality 

 of mental facts, that is itself, as Hamilton remarks and as we shall 

 find immediately, incapable of being exactly defined. Still, it is 

 possible to furnish some conceptions regarding the distinctive nature 

 of the objects to which the several sciences are devoted ; and it is 

 sufficient, as it is essential, that such conceptions should be clear and 

 accurate enough to give a definite direction to the labours of students. 

 Had Sir W. Hamilton uniformly, as he seems to have at times, made 

 consciousness the differentia of all mental action and passion, he 

 would have avoided a perplexity which it is now difficult to remove. 

 As this perplexity has arisen from his referring certain actions of the 

 nervous system to an unconscious agency of the mind, the further 

 consideration of our present subject may be deferred till we have 

 discussed his explanation of those nervous actions. 



Since Sir William Hamilton holds that consciousness is the indis- 

 pensable condition, if not of all mental states, at least of all mental 

 phenomena, we may now inquire what he understands by conscious- 

 ness. It has been already observed in passing that he maintains 

 consciousness to be incapable of definition in the strict sense of the 

 word, inasmuch as there is no more elementary fact by means of 

 which it could be rendered clearer ; and in this he will probably be 

 sustained by the most of philosophers. But while he considers con- 

 sciousness to be incapable of definition, he holds that it may be 

 philosophically analysed. By referring to my exposition of his 

 system it will be found that his analysis yields the following three 

 factors as required to constitute every act of consciousness: (1) A 

 mind or subject which knows ; (2) a modification of that mind ; (3) 

 a recognition or knowledge by the mind of the modification. At the 

 first glance nothing may seem more distinct than this analysis ; and 

 in the writings of some philosophers, even after matured examin- 

 ation, it might be found incapable of being misunderstood. As it 

 stands, however, it must be taken in connection with the rest of Sir 

 William Hamilton's philosophy ; and in this connection it suggests 

 several questions which cannot be easily or satisfactorily answered. 



