THEORIES CONCERNING AXIOMS. 295 



or not." "For our primary beliefs, the fact of invariable 

 existence, tested by an abortive effort to cause their non- 

 existence, is the only reason assignable." He thinks this the 

 sole ground* of our belief in our own sensations. If I believe 

 that I feel cold, I only receive this as true because I cannot 

 conceive that I am not feeling cold. " While the proposition 

 remains true, the negation of it remains inconceivable." 

 There are numerous other beliefs which Mr. Spencer considers 

 to rest on the same basis ; being chiefly those, or a part of 

 those, which the metaphysicians of the Reid and Stewart 

 school consider as truths of immediate intuition. That there 

 exists a material world ; that this is the very world which we 

 directly and immediately perceive, and not merely the hidden 

 cause of our perceptions ; that Space, Time, Force, Extension, 

 Figure, are not modes of our consciousness, but objective 

 realities; are regarded by Mr. Spencer as truths known by 

 the inconceivableness of their negatives. We cannot, he says, 

 by any effort, conceive these objects of thought as mere states 

 of our mind ; as not having an existence external to us. Their 

 real existence is, therefore, as certain as our sensations them- 

 selves. The truths which are the subject of direct knowledge, 

 being, according to this doctrine, known to be truths only 

 by the inconceivability of their negation; and the truths 

 which are not the object of direct knowledge, being known 

 as inferences from those which are ; and those inferences 

 being believed to follow from the premises, only because we 

 cannot conceive them not to follow; inconceivability is thus 

 the ultimate ground of all assured beliefs. 



Thus far, there is no very wide difference between Mr. 

 Spencer's doctrine and the ordinary one of philosophers of the 

 intuitive school, from Descartes to Dr. Whewell; but at this 

 point Mr. Spencer diverges from them. For he does not, like 

 them, set up the test of inconceivability as infallible. On the 

 contrary, he holds that it may be fallacious, not from any fault 

 in the test itself, but because " men have mistaken for incon- 

 ceivable things, some things which were not inconceivable." 

 And he himself, in this very book, denies not a few proposi- 

 tions usually regarded as among the most marked examples 



