we should understand how it is
to happen. It is not necessary, and in a thousand instances we do not
know. "If we take poison, we shall die:" there is a statement which we
can understand, and therefore believe. But do we understand how it is
that poison kills us? Does every one here know how poisons act upon the
human frame, and what is the different operation of different
poisons,--how laudanum kills, for instance, and how arsenic? Surely
there are very few of us, at most, who do understand this: and yet would
it not be exceedingly unreasonable to refuse to believe that poison will
kill us, because we do not understand the manner _how_?

Thus far, I think, the question is perfectly plain, so soon as it is
once laid before us. But the real point of perplexity is to be found a
step further. In almost all propositions there is something about the
terms which we do understand, and something which we do not. For
instance, let me say these few words:--"A frigate was lost amidst the
breakers." These words would be understood in a certain degree, by all
who hear me: and so far as all understand them, all can believe them.
All would understand that a ship had sunk in the water, or been dashed
to pieces; that it would be useful no more for the purposes for which it
had been made. But what is meant by the words "frigate" and "breakers"
all would not understand, and many would understand very differently:
that is to say, those who had happened to have known most about the sea
and sea affairs would understand most about them, while those who knew
less would understand less; but probably none of us would understand
their meaning so fully, or would have so distinct and lively an image of
the things, as would be enjoyed by an actual seaman; and even amongst
seamen themselves, there would again be different degrees of
understanding, according to their different degrees of experience, or
knowledge of ships, or powers of mind.

I have taken the instance at random, and any other proposition might
have served my purpose as well. But men do not speak to one another at
random; when they say anything to their neighbour, they mean it to
produce on his mind a certain effect. Suppose that we were living near
the sea-coast, and any one were suddenly to come in, and to utter the
words which I have taken as my example: should we not know that what the
man meant by these words was, that there was a danger at hand for which
our help was needed? It