And, though the weight of reasons cannot be taken with the precision of algebraic quantities, yet, when each is thus considered, separately and comparatively, and the whole lies before me, I think I can judge better, and am less liable to make a rash step; and in fact I have found great advantage from this kind of equation, in what may be called moral or prudential algebra. (To Joseph @Priestley, September 19, 1772)
SCIENTIFIC PROGRESS. The rapid progress true science now makes, occasions my regretting sometimes that I was born so soon. It is impossible to imagine the height to which may be carried, in a thousand years, the power of man over matter. We may perhaps learn to deprive large masses of their gravity, and give them absolute levity, for the sake of easy transport. Agriculture may diminish its labor and double its produce; all diseases may by sure means be prevented or cured, not excepting even that of old age, and our lives lengthened at pleasure even beyond the antediluvian standard. O that moral science were in as fair a way of improvement, that men would cease to be wolves to one another, and that human beings would at length learn what they now improperly call humanity! (To Joseph Priestley, February 8, 1780)
HUMANITY. I should rejoice much, if I could once more recover the Leisure to search with you into the Works of Nature; I mean the inanimate, not the animate or moral part of them, the more I discovered of the former, the more I admired them; the more I know of the latter, the more I am disgusted with them. Men I find to be a sort of beings very badly constructed, as they are generally more easily provoked than reconciled, more disposed to do mischief to each other than to make reparation, much more easily deceived than undeceived, and having more pride and even pleasure in killing than in begetting one another; for without a blush they assemble in great armies at noonday to destroy, and when they have killed as many as they can, they exaggerate the number to augment the fancied glory; but they creep into corners, or cover themselves with the darkness of night, when they mean to beget, as being ashamed of a virtuous action. A virtuous action it would be, and a vicious one the killing of them, if the species were really worth producing or preserving; but of this I begin to doubt.
I know you have no such doubts, because, in your zeal for their welfare, you are taking a great deal of pains to save their souls. Perhaps as you grow older, you may look upon this as a hopeless project, or an idle amusement, repent of having murdered in mephitic air so many honest, harmless mice, and wish that to prevent mischief, you had used boys and girls instead of them. In what light we are viewed by superior beings, may be gathered from a piece of late @West @India news, which possibly has not yet reached you.
A young angel of distinction being sent down to this world on some business, for the first time, had an old courier-spirit assigned him as a guide. They arrived over the seas of @Martinico, in the middle of the long day of obstinate fight between the fleets of @Rodney and @De @Grasse. When, through the clouds of smoke, he saw the fire of the guns, the decks covered with mangled limbs, and bodies dead or dying; the ships sinking, burning, or blown into the air; and the quantity of pain, misery, and destruction, the crews yet alive were thus with so much eagerness dealing round to one another; he turned angrily to his guide, and said, "You blundering blockhead, you are ignorant of your business; you undertook to conduct me to the Earth, and you have brought me into Hell!
