Do 形容詞 have a 未然形 in Classical Japanese?


I was reading Eiríkr Útlendi's
[answer](https://japanese.stackexchange.com/a/16228/3437) about -い vs. -き in
形容詞 and noticed that he identified -く as the 未然形 of 形容詞. When I studied
classical Japanese, though, I was taught that 形容詞 lack a 未然形 (and also lack a
命令形, of course).

This jives with my (probably poor) intuition about how 形容詞 conjugate - you
can't say *美しくず or *美しくぬ for the negative of 美し - you have to say 美しくあらず or
美しからぬ or something like that (i.e. using the 連用形, which is 美しく, adding an あり,
and then tacking a negation 助動詞 onto the 未然形 of あり, which is あら).

Are there multiple schools of thought on whether or not 形容詞 have a 未然形? The
textbook I used was [新編文語文法 by
大野晋](http://www.amazon.co.jp/gp/product/4482000620/), in case that helps.

* * *

UPDATE: I found my textbook; it states the following in the section on
形容詞の活用の種類 (p. 30): for the ク活用, we have two patterns of conjugation
(未然・連用・終止・連体・已然・命令):

[code]

     1.　　 〇　　　　　―く　　　　　―し　　　　　―き　　　　　―けれ　　　　 〇
     2.　　―から　　　　―かり　　　（―かり）　　　―かる　　　（―かる）　　　―かれ
    
[/code]

Likewise, we have two patterns of conjugation for シク活用:

[code]

     1.　　 〇　　　　　―しく　　　　―し　　　　　―しき　　　　―しけれ　　　 〇
     2.　　―しから　　　―しかり　　（―しかり） 　　―しかる　　（―しかる）　　―しかれ
    
[/code]

The textbook does not specifically name the (2.) conjugations as the カリ活用 and
シカリ活用, but does mention them. In any case, the textbook specifically claims
that in their "bare" form (without あり), 形容詞 do not have a 未然形 (p. 31; emphasis
added):

> 「ク活用」「シク活用」のいずれの場合も、本来の活用は「〇・く・し・き・けれ・〇」「〇・しく・し・しき・しけれ・〇」で、 **未然形・命令形がなかった**
> 。それでは助動詞に続かず不便なので、のちに、それを補うために、連用形のあとにラ変動詞「あり」をつけて、「高く＋あり→高かり」のように熟合させたのが[the
> (2.) conjugations]である。これによって未然形・命令形を補うと共に、助動詞との接続が自由になった。




The use of the 未然形 is quite limited. As 形容詞 don't conjugate like verbs, it's
hard to say they have the 未然形.

But as far as I know, there are several theories claiming 形容詞 do have 未然形:

  1. く is the 未然形. ～くば resembles 動詞未然形＋ば, which is the conditional from.

  2. く is the 未然形. ～くない resembles 動詞未然形＋ない, which is the negative form.

  3. け is the 未然形. ～けく resembles 動詞未然形＋く, which is known as the ク語法.

  4. から is the 未然形. ～からず resembles 動詞未然形＋ず.

  5. け is the 未然形. ～けむ resembles 動詞未然形＋む, which is the future/volitional form.

1 is just a coincidences. は, ずは, ずんば, etc. have the same function, too.

So is 2.

3 doesn't etymologically make sense to me.

* * *

If you look at the auxiliaries that accept the 未然形, you will find they are
full of irregularities. e.g.

ない：（サ変）しない；（カ変）こない；（一段）みない、

まい：（サ変）しまい／すまい／するまい／せまい；（カ変）こまい／くまい／くるまい；（一段）みない、みるまい；（二段）うけまい／うけるまい

べし, す and る are irregular too. ず, ぬ and む are relatively regular, though.

Except ず, ぬ and む, you can't derive the proper form for most regular verbs
solely by attaching the auxiliary to the 未然形 of the verb. The regularity of ず
might be simply because 未然形 was defined as the form required by ず, as its name
implies.

