Dick,
I think that the main problem here is just a matter of definitions.
There are the Static and the Dynamic stability.
Static stability refers to the aircraft's initial response when disturbed from a given angle of attack, slip or bank.
Dynamic stability refers to the aircraft response over time when disturbed from a given angle of attack, slip or bank.
Further there are:
Positive stability (tends to return to original condition).
Negative stability (tends to increase the disturbance - undesirable in most situations)
Neutral Stability (remains at new condition - does not move further away or closer)
If we mix them altogether we may get:
Positive Static stability, Negative Static stability Neutral Static stability or
Positive Dynamic stability, Negative Dynamic stability, Neutral Dynamic stability, etc.

To make a long story short, I would say:

For me, a totally stable aircraft will (after a disturbance) return, more or less immediately, to its trimmed state without pilot intervention.

However, such an aircraft is rare and not much desirable as we usually want an
aircraft just to be reasonably stable so it is easy to fly.
If it is too stable, it tends to be sluggish in manoeuvring, exhibiting too slow
response on the controls.

Too much instability is also an undesirable characteristic, except where an
extremely manoeuvrable aircraft is needed and the instability can be continually
corrected by on-board 'fly-by-wire' computers rather than the pilot, such as a
supersonic air superiority fighter.

So, an aircraft that needs constant corrections during the flight either done by the pilot or by a computer is not considered stable even if it is flyable.
That's why stability is not a moving target it is just stability...