They had to make good their own claims and to displace rival documents; and they succeeded.

It is a striking instance of the 'survival of the fittest.' That they were really the fittest is confirmed by nearly every fragment of the lost Gospels that remains, but it would be almost sufficiently proved by the very fact that they survived.
In this indirect manner I think that the external evidence bears out the position assigned to the canonical Gospels.

It has preserved to us the judgment of the men of that time, and there is a certain relative sense in which the maxim, 'Securus judicat orbis terrarum,' is true.

The decisions of an age, especially decisions such as this where quite as much depended upon pious feeling as upon logical reasoning, are usually sounder than the arguments that are put forward to defend them.

We should hardly endorse the arguments by which Irenaeus proves _a priori_ the necessity of a 'four-fold Gospel,' but there is real weight in the fact that four Gospels and no more were accepted by him and others like him.