the concept it reflects is a very common one. The notion of a person being 'willing-unwilling' drawn into singing a song, or dancing, etc. is quite useful, I think.

Not sure I would agree that this is the concept behind "nolen volens", belligerentyouth, although I do agree that that seems to be the sense behind your Geothe quotation as interpreted in this discussion which I found online.

nolens volens - (lat. wanting not-wanting) half voluntarily half involuntarily. Goethe (Fischer): half it pulled it, half sank it."

The Professor who cited Goethe's 'push-pull' idea [being "of two minds" about something, or being "pulled in two different directions"] is not seeing the implicit "or" in "nolens volens", I believe.

It is not "nolen volens" I submit, but "nolens [or] volens" as in this discussion of the term:

Word of the Day for Monday June 28, 2004 - Dictionary.com
nolens volens \NO-lenz-VO-lenz\:
Whether unwilling or willing.

"Beneath the surface, little-noticed but fundamental changes are taking place that must compel both sides, nolens volens, sooner or later to reconfigure their tortured but inseparable relationship."
--Bernard Wasserstein, Israelis and Palestinians

Please note "compel" in quotation. Whether they choose, or not, they must, inevitably they will, find a modus vivendi. Like "yin and yang", tail and fang, locked in an endless, circular chase/embrace.

Would this express your idea [and Goethe's] of being "willing-unwilling" both at the same time, BY?

Everything can be described as yin or yang

1. Yin and yang are opposites.

Everything has an opposite. Though it is never absolute, only comparative. However, no one thing is completely yin or completely yang. It contains the seed for it's opposite. For example, cold can turn into hot; "what goes up must come down".

2. Yin and yang are interdependent.

One cannot exist without the other. For example, day cannot exist without night.

3. Yin and yang can be further subdivided into yin and yang.

Any yin or yang aspect can be further subdivided into yin and yang. Take temperature for example. It can be considered hot or cold, but can also be further divided into warm and burning, or cool and icy.

4. Yin and yang consume and support each other.

Yin and yang are constantly kept in balance. As one increases, the other decreases. However, imbalances can occur. There are four possible imbalances: Excess yin, excess yang, yin defeciency, yang deficiency.

5. Yin and yang can transform into one another.

At a particular stage, yin can transform into yang and vice versa. For example, night changes to day ; heat turns to cool; life changes to death.

http://en.wikipedia.org/wiki/Yin_Yang

P.S. I was surprised to see that I was part of that "volens" discussion a year ago, BY.

And, yes, it does have "a good rind to it". :)