SIR WILLIAM Hamilton's philosophy. 65 



popular language, ■which is satisfied with describing the superficial 

 appearance of things, but it is far from easy to define with scientific 

 exactness, the object of which I am conscious in an act of external 

 perception. Let it however be supposed that this is not so difiicult as 

 it is in reality, we are still far from having determined with precision, 

 what the testimony of consciousness is in such an act ; and we are thus 

 brought to a second source of the error into which Hamilton has fiillen. 

 We may suppose that every necessary precaution has been taken to 

 discover and to describe exactly the phenomenon of consciousness which 

 we are now discussing, and that, after the labours of numerous obser- 

 vers and writers have been employed on it, we are now in a position to 

 declare a certain statement universally accepted. It will, I believe, be 

 acknowledged by all, though not perhaps in the very same terms, that 

 external perception is an apprehension of something which appears at 

 least to be different from the perceiving mind, as well as to be existent 

 in time and in space ; and that this apprehension bears from the very 

 first so strong an appearance of immediateness, that it is taken by the 

 unrefiective mind to be from the very first really immediate. Sir "W". 

 Hamilton's theory is, that the testimony of consciousness is thus com- 

 mitted to the doctrine of the real or oi-ii/inal immediacy of external 

 perception, and that consequently the denial of this doctrine necessarily 

 involves the rejection of that testimony. Xow, in citing the authority 

 of consciousness as in favour of any theory, there are certain laws by 

 which Sir W. Hamilton taught his pupils to be guided. One of these, 

 which he names the Law of Parsimony, enjoins '• that nothing be 

 assumed as a fact of consciousness but what is ultimate and simple." 

 In explaining this law he asks,* " "What is a fiict of consciousness ? 

 . . . . In the first place, every mental phenomenon may be called 

 a fact of consciousness. But as we distinguish consciousness from the 

 special faculties, though these are all only modifications of conscious- 

 ness — only branches of which consciousness is the trunk, so we distin- 

 guish the special and derivative phenomena of the mind from those 

 that are primary and universal, and give to the latter the name of /acts 

 of consciousness, as more eminently worthy of that appellation. In an 

 act of perception, for example, I distinguish the pen I hold in my hand, 

 and my hand itself, from the mind perceiving them. This distinction 

 is a particul^.r fact — the fact of a particular faculty, perception. But 



* Zfc. on JTdaph., vol. L, p. 260. See also HeiSs Works, pp. *r4^9-50. 



