227 
find the great importance of having settled the meaning of 
the verb “ to know/' Berkeley is the great teacher of the 
non-existence of material substances as such. He says, 
“ It is indeed an opinion strangely prevailing amongst men, 
that houses, mountains, rivers, and, in a word, all sensible 
objects, have an existence natural and real, distinct from their 
being perceived by the understanding. But with how great an 
assurance and acquiescence soever this principle may be enter- 
tained in the world ; yet whosoever shall find in his heart to 
call it in question, may, if I mistake not, perceive it to involve 
a manifest contradiction. For what are the forementioned 
objects but the things we perceive by sense, and what do we 
perceive besides our own ideas or sensations; and is it not 
Plainly repugnant that any of these, or any combination of 
them, should exist unperceived ? ” * It is not difficult to see 
where the foundation of this absurdity lies. Berkeley, in 
following Locke, takes it for granted that we have no percep- 
tion of external objects, but only of sensations and ideas m 
our minds. He has no thought that perception may be a state 
of the mind as truly and directly produced and maintained by 
an external object as sensation. He does not even imagine 
that a sensation itself can be only a temporary state of the 
sentient being, produced by means of an external material 
object. If he admits even this, his theory is gone, for the 
external object must exist in order to its being the means of 
producing the sensation. It is not difficult, we think, to 
explain satisfactorily this “ strange impossibility,” which the 
philosopher says stood in the way of his even imagining the 
existence of the world apart from his sensations and percep- 
u° n ?' Tlie p( ? 01 ful1 of fi . ahes is a fair illustration of his case. 
He had committed the mistake of imagining sensations and 
ideas as realities in themselves, and not merely modes of him- 
self as a sentient and intelligent being. He had admitted an 
ideal world consisting of these sensations and perceptions to 
come between him and the real world with its "ever- 
lasting hills.” He had allowed this ideal world to become 
so vivid and fixed in his imagination that he could see nothing 
through it. His illusion was so perfect that there was not any 
tiling m his philosophic universe of a real nature but this ideal 
dream itself Yet this mistake ought not to mislead any careful 
thinker. We have in man a being capable of affections from 
matter, which we call sensations— but capable also of affections 
rom the same matter, which we call ideas, thoughts, perceptions 
-these affections being nothing more or less than states of 
Berkeley's Works , Vol. I., p. 25, edition 1784. 
