Excellence

The quality of being excellent is purely contextual. Something is said to excel when it rises above its surroundings, its context, or its neighbours. It follows therefore that nothing can be excellent unless it is compared to something else. Indeed, excellere is the Latin for 'to be made loftier (than something else)'.

In that sense, it is related to another Latin word, excedere — 'to go or pass beyond (something else)'. It is where we get the words 'exceed' and 'excess'. If something is excellent, it is excessive in the vertical sense.

Excellence, therefore, is excess. It may be useful to strive for excellence, but excellence in itself relies on comparison. Take away the context, and excellence fails in itself.

But this is true of many other things. Perhaps it is good to compare the words 'abnormal' and 'enormous'. Both are comparisons with 'normal' — the former means 'away from the norm', while the latter means 'out of the norm'. I leave you to decide which is better.