William Hazlitt, On the Pleasure of Hating.
It is easy to raise an outcry against violent invectives, to talk loud against extravagance and enthusiasm, to pick a quarrel with every thing but the most calm, candid and qualified statement of facts: but there are enormities to which no words can do adequate justice.
Are we then, in order to form a complete idea of them, to omit every circumstance of aggravation, or to suppress every feeling of impatience that arises out of the details, lest we should be accused of giving way to the influence of prejudice and passion? That would be to falsify the impression altogether, to misconstrue reason, and fly in the face of nature.
Suppose for instance, that in the discussion of the Slave-Trade, a description to the life was given of the horrors or the Middle Passage (as it was termed), that you saw the manner in which thousands of wretches, year after year, were stowed together in the hold of a slave-ship, without air, without light, without food, without hope, so that what they suffered in reality was brought home to you in imagination, till you felt in sickness of heart as one of them, could it be said that this was a prejudging of the case, that your knowing the extent of the evil disqualified you from pronouncing sentence upon it, and that your disgust and abhorrence were the effects of a heated imagination? No. Those evils that inflame the imagination and make the heart sick, ought not to leave the head cool.
This is the very test and measure of the degree of the enormity, that it involuntarily staggers and appalls the mind. If it were a common iniquity, if it were slight and partial, or necessary, it would not have this effect; but it very properly carries away the feelings, and (if you will) overpowers the judgment, because it is a mass of evil so monstrous and unwarranted as not to be endured, even in thought.