Tertullian · a new plain-English translation from the original language
Take fever, for instance, allotted to man among the other fatal and torturing forms of death: we are not astonished either that it exists—for exist it does—or that it destroys a man—for that is what it is for. [2] Likewise, if heresies have been produced for the sickening and death of faith, and we are terrified that they can do this, we ought first to be terrified that they exist at all—for while they exist, they have the power to do it, and while they have the power, they exist. [3] But fever, an evil in its origin and, notoriously, in its effect alike, we loathe rather than marvel at, and we guard against it as far as lies in us, though we do not have its abolition in our own power. [4] Heresies, however, bringing eternal death and the burning of a greater fire, some prefer to marvel at, for the very fact that they have such power, rather than to shun them, when they can, having the power to shun them. [5] For the rest, they will have no power at all, if people simply refuse to marvel that they have such power. For either, by marveling, men provide the very stumbling-block, or else, because they are scandalized, they marvel—as though the very fact that heresies have such power must come from some truth in them. [6] Marvelous indeed, that an evil should have force—unless it is simply that heresies have great power precisely among those who have no power in their faith. [7] In a contest of boxers and gladiators, more often than not the winner is not the one who is strong, or who cannot be beaten, but rather the one who wins does so because his opponent had no strength at all in him: thus that very same victor, matched afterward against a man in good condition, comes off beaten in his turn. [8] It is no different with heresies: what power they have comes from certain persons' weaknesses—they have no power at all if they run up against a faith in good health.