i88i.] The Inconceivable as a Test of Truth. 149 
therefore, that these propositions are certain, and that we 
have no other certain knowledge, is to say that there 
is no other proposition for which we would claim certainty, 
of which the contradictory is not conceivable in the sense 
which I have proposed for that term. All those, there- 
fore, who assert that we have not the like certainty of any 
other proposition, are bound, if any proposition is offered 
to them as of equal certainty, to be prepared to say 
that they can and do conceive the contradictory of that pro- 
position as possibly true in some other sphere and possibly 
apparent in another state of enlightenment. If reason ab- 
solutely refuses the possibility of the contradictory, it ipso 
facto affirms the independent and absolute truth of the pro- 
position. To illustrate this, let the idea be that of a man 
reclining in a blast-furnace drinking melted marble ; or of a 
temperature that would freeze the flame of a lamp, so that 
it should be gradually forced upward in the form of a pel- 
lucid cone ; or of hydrogen stored in blocks to be split up for 
fuel, or of preserving the heat of the dog-days in casks to 
temper the severity of the winter. These ideas are quite 
opposed to experience, but there is no contradiction present. 
They are conceivable. Again, a region where the attraction 
of gravity was replaced by repulsion, so that houses had to 
be screwed into the ground, &c. ; or where people were born 
in a state resembling old age, and after passing through 
maturity, youth, and childhood, attained to infancy and 
then died; or where a man could detach a diseased organ 
from his body and leave it with the physician for repair as 
he would his watch with the watchmaker. All these are 
ideas which experience does not aid us to realise, but reason 
stands neutral. There is no contradiction ; they are not in- 
conceivable, therefore not necessarily false ; and a rational 
man is bound to say that such things could be. Any convic- 
tion that we may feel that they are not is only subjective, or, 
in plain English, matter of opinion. But let the suggestion 
be of a region where things and conditions of things begin 
to be, without anything making them begin to be ; or where 
things can be conscious of thought without existing ; or 
where a number of lines in one plane, intersecting at one 
point, can make angles exceeding in sum those made by the 
first two; or where there can be merit without intention, or 
guilt without free will ; or where there may be limits to space 
and no space beyond those limits, that is to say, beyond those 
limits neither something nor nothing; or where there is no 
duration or succession, but all things are simultaneous; or 
where there is no number, but 1000 may be sometimes more, 
