175. The "Negative" Radical: 非
The graceful, flowing 非 shape is so lovely that I have no negative feelings about it whatsoever. All the same, 非 is called the "negative" radical in English because it looks just like this negating kanji:
非 (773: not, non-, un-; wrong)
"Wrong," "injustice," and "not" are alternative names for the radical.
Meanwhile, the Japanese call it あらず, which is hardly intuitive. After all, the Joyo yomi of the 非 kanji is ヒ, whereas あら•ず is a non-Joyo kun-yomi (and is the negative form of ある (to be; exist) in archaic Japanese). I believe that someone associated 非 with あら•ず because it sounds quite distinctive, whereas these other radicals are called ひ:
匕 (radical 21: "spoon"), though that's the least-common name
日 (radical 72: "sun")
火 (radical 86: "fire")
The eight-stroke 非 radical has no variants and is on duty only in 非 (773).
Photo Credit: Eve Kushner
The Etymology
Henshall says in his newer edition that 非 etymologically depicts the "outstretched wings of a bird in flight." No wonder this shape is so elegant! He adds that ancient people came to use "outstretched wings" to convey "mutually opposed," which extended to negative senses such as "not" and "fault."
How did something so positive become so negative?!