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traced in several sceptical arguments. I may call it tlie fallacy 
of supposed uniformity. The law on which all analytical argu- 
ment depends I have termed the law of uniformity ; but before 
we press such an argument, we must be sure that the uni- 
formity really exists. If we are not certain of this, we shall 
be liable to fall into the error of making cause disproportionate 
to effect, or effect to cause. The most remarkable instance of 
this fallacy is to be found in the arguments alleged against 
Scripture history, drawn from the thickness of deposits on the 
banks of the Nile and elsewhere, and from the finding of pieces 
of pottery at a depth in alluvial soil, which seem to show that 
human art existed many centuries before the period which the 
Bible seems to assign to the creation of man. All these argu- 
ments depend on the supposition that deltas and other alluvial 
deposits are uniform in their growth ; that a river blunging 
down silt with it deposits exactly the same thickness yearly 
now that it deposited thirty-five centuries ago ; and that we 
may accordingly calculate unerringly, from the depth of a 
deposit, and the present rate of its deposition, how many 
years, or millions of years, have elapsed since the first layer 
assumed its place. But is this true ? I apprehend that those 
who have been at the mouth of the San Juan, or the 
Aspro-potamo, or in the Chinese seas, will be of a different 
opinion. The rate of deposition is not necessarily uniform ; 
and the potsherds found deepest in the Nile mud need not be 
earlier than the time of the first settlement on its banks under 
Men the Hamite. 
I come now to the third logical process, that from one 
individual relation to another, guided by the law which I call 
the law of analogy. What the fallacy is to which this process 
is liable, we may easily see. The guiding law is violated by 
passing in thought from one individual to another which is not 
really but only apparently similar; by contenting ourselves 
with a hypothetical likeness, and so employing a false, not a 
real, analogy. The tendency in our minds, which I have 
already pointed out, to prefer the process from individual to 
individual, renders this fallacy of false analogy one of the 
commonest and yet often least easy to detect. The most effec- 
tual mode of exposing it seems to be that of completing the 
whole intellectual route, aud, instead of passing directly from 
individual to individual, supplying the law of general proba- 
bility under which both come. If I throw up a stone and find 
that it turns and falls down, I infer that if I throw up another 
it will do the same. The mind passes from individual to indi- 
vidual by the law of analogy. This law is really subordinate 
to that of uniformity, and each analogy, to be correct, ought 
