Nancy Friedman, whom you may know as @Fritinancy, tweets this morning: “Have seen 2 examples this morning of "loathe" (verb) where "loath" (adj.) is needed. Time to give up this fight?”
To the barricades, citizens!
Both are very old words in English.
Loath, or loth, meant “hostile” or “repugnant” or “ugly” at one time or another until the sense of “averse,” “reluctant,” “unwilling” became dominant. Chaucer uses this sense in describing the Wife of Bath. The OED’s earliest citation of loathe, for “to feel disgust,” is from The Destruction of Troy in 1400.
Though their etymologies differ—loath from various Germanic cognates for “sorrow,” “pain,” loathe from Germanic forms of “to hate”—the spellings switched back and forth until orthography became standardized. The pronunciations, while close, are not identical.
The spelling is the problem, and people’s tendency to confuse the spellings blurs an important differentiation.
To be loath to do something is relatively understated emotionally. It is the equivalent of Melville’s Bartleby saying, “I would prefer not to.”
But to loathe is of a much higher intensity. If I loathe something, I am not reluctant to express my sentiments. I dislike it. I more than dislike it. I detest it. I despise it! IT IS A STENCH IN MY NOSTRILS!*
The difference in emotional intensity is a difference in meaning, and an important one. It would be a loss to the language to lose that distinction merely because some people have trouble with their spelling.
I, for one, am holding firm. Who will stand with me?