530 PROFESSOR ALISON ON THE BELIEF 
sensations, but which is no sooner apprehended than it “ swells in the human 
mind to Infinity,” to which notion certainly no human sensation can bear any 
resemblance; and no one has rightly apprehended the argument, or can be aware 
of the importance ascribed to it by Mr Stewart, as opposed to what has been 
since called the Sensational School of Metaphysicians, who has not adverted to 
this absolute and essential dissimilarity of the sensations, from what Dr Rerp calls 
“the Perceptions,” and Dr Brown, the “ Associations and Inferences,” consequent 
on those sensations. Those who do advert to that dissimilarity must perceive 
that our conception of, and belief in, the external and independent existence of 
space and matter,—although a mental act, and a complex one, and involving 
one of those intuitive judgments, as to the existence and authority of which we 
have seen that Rerp, Srewart, and Browy, are fully agreed,—is perfectly distinct 
from the sensation by which it is excited, and involves no such absurdity or con- 
tradiction in terms, as the assertion that a sensation or other mental act, can be 
the exact image and representation of anything that is not mental; and therefore, 
that the sceptical argument of BrrKELey and Hume, founded on that supposed 
absurdity, and necessitating our departure, as HuME expressed it, from the in- 
stincts of nature, as to the evidence of the senses, falls to the ground. 
The same observation applies to the notice of this subject by Moret, in his 
review of the Scottish Philosophy, who says, that Dr Rem “ does not appear to 
him to have dealt a complete and effective blow against Humr’s argument respect- 
ing the material world ;” because, he says, “ the sceptic may urge, with no little 
force, that although we must admit the reality of our own personal or subjective 
ideas (i. ¢., of the objects of consciousness), yet it still remains to be proved, that 
our perceptions, however clear, and our beliefs, however strong they may be, in- 
ternally, have reference to any object out of, and distinct from ourselves.” Retp, 
he says, deprived himself of the “ power of answering this final argument, by 
maintaining that Perception is altogether an act of Mind. So long as perception 
is regarded as only a subjective process (7. ¢., an act of mind of which we are con- 
scious), and an idea defined to be the act of the mind in making itself acquainted 
with external things, we are unable to point out to the sceptic what he demands, 
viz., a clear passage from this subjective activity of the mind to the outward and 
material reality.” —(Morell's Philosophy, vol. i., p. 287.) 
Now, if this author had rightly comprehended the argument of Rerp,—which 
I apprehend he must have known only from the account of the controversy given 
by Dr Brown,—he would have known that Rep considered the clear passage from 
the act of Perception in the mind to the material reality, to be precisely similar to 
the passage from our consciousness of to-day to our recollections of yesterday ; 7. e., 
to rest on one of those principles of Intuitive belief, the ea?stence and authority of 
which are admitted by himself and by Brown, as well as by Rein; and to be 
from its own nature incapable of any other proof. 
