100 PROF. H. LANGHORNE ORCHARD, M.A., B.SC., ON 
“miracle” or set of “ miracles” must be investigated separately, 
and stand or fall on its own merits according as it does, or does 
not, satisfy the tests. 
In connection with the value of testimony, it may be pointed 
out that it varies with the probability that what the witness 
states is fact, which probability will have two factors—the 
antecedent probability of the event, and the probalility that 
the witness is truthful and competent, 7.e., that he is neither a 
deceiver nor Ceceived. 
If a person relates that he has just seen a brown dog running 
alone the road we believe it as a matter of conrse, unless we 
have grounds for thinking him to be a liar: if he says that he 
has seen a white blackbird we may think that he is mistaken 
or false, and if he told us that without any visible means he 
had been communicating in converse with people more than a 
thousand miles away (and we did not know anything of wire- 
less telegraphy) then, on account of the antecedent improbability 
—as we suppose—of this event, we should probably attach no 
value to his testimony, unless upon other grounds we knew 
that it must be trustworthy. Yet, granted the narrator’s 
truthfulness, our reluctance to believe would be attributable 
to our ignorance. Thus, what is probable (or improbable) to 
us is dependent upon our knowledge of the matter. What 
seems to us to disagree from known truth (or, from what is 
believed to be so) is to us improbable; what neither disagrees 
nor agrees is neither improbable nor probable; what agrees is 
probable, and if the measure of agreement is, on the whole, 
very great, then the probability is very great. As regards the 
event itself, its occurrence or non-occurrence is certain, and 
entirely independent of our ideas; but our view of its proba- 
bility (or otherwise) is necessarily conditioned by the quality 
and the quantity of knowledge, with regard to this or to some 
similar event, already in our possession. 
We see then that, since what is to us improbability or 
probability is dependent upon our actual knowledge of the 
matter, the judgment of science concerning miracles in general, 
i.e., miracles considered simply as miracles, is that they are not 
a priori improbable, and may or may not be probable. And, 
concerning any particular case, science enjoins that it be con- 
sidered specially and on its own merits, with the application of 
the three tests already mentioned. 
(c) Let us now ask science whether miracles have actually 
occurred. Science answers in the affirmative. She tells us 
that events have undoubtedly taken place which come within 
