y on a probability, and that he believed in Catholicism on
a probability, and that these three grounds of probability, distinct
from each other in subject-matter, were still, all of them, one and
the same in nature of proof, as being probabilities--probabilities of
a special kind, a cumulative, a transcendent probability, but still
probability.

But did he not by some magical metamorphosis turn these probabilities
into a certainty? No; he simply claimed that they were sufficient to
produce certitude, which is a different matter. Certitude, he held,
was a quality or habit of mind; certainty, a quality of propositions;
and probabilities that did not reach to logical certainty might
suffice for a mental certitude. We are mentally sure almost every day
of many things which could not be demonstratively proved; we are
practically as sure of them as if they could be proved; we are ready
to act on the basis of them, and that is the test of practical
certitude. The word of a friend on a matter of which we are ignorant
is an example; we may be as sure of what he tells us as if we had seen
it ourselves; yet he may be mistaken; strictly speaking, his word is
only probable evidence. But did not Newman substitute faith for
reason? Yes, in a sense; but not in a sense in which it is of itself
irrational to do so. How much could the reason of any of us tell us of
Central Africa? We know of it by testimony, do we not? not by reason.
From our own notions alone we could not tell whether it was a desert
or a forest; whether it was inhabited or uninhabited; whether
full-grown human beings or dwarfs lived there; but a Livingstone, a Du
Chaillu, a Stanley, tell us, and we accept their word. The fact is,
that trust in testimony is what we daily practise. We learn of what is
going on in a neighboring town, of much in our own town, of much in
our own house (unless we are there all the time, and in every part of
it at the same time) not by reasoning about it, any more than by
sight, but by faith in what others tell us. "Why should we be
unwilling to go by faith?" asks Newman. "We do all things in this
world by faith in the word of others. By faith only we know our
positions in the world, our circumstances, our rights and privileges,
our fortunes, our parents, our brothers and sisters, our age, our
mortality; why should religion be an exception? Why should we be
willing to use for heavenly objects what we daily use for earthly?"
There is really no