You write that ‘radiance is virtue manifested in the keys of natural eloquence, graceful action, and a gentle demeanor…’ So, does radiance consist of three different things that, once combined, make up a whole, or are these three names for the same thing? 

The latter. Radiance is not a part:whole relationship (fingers:hand) or an arithmetic relationship (1 + 1 + … + = n). Radiance is the same thing manifesting itself fully in three different ways.

When the radiant person acts (or rests), he acts (or rests) in the right sort of way. When he speaks (or is silent), he speaks (or is silent) in the right sort of way. When he demeans, he demeans in the right sort of way. The last is concerned with the kind of presence he conveys. It may be that his absence (or ultimate absence) also leaves others uplifted, as if he were still present in the right sort of way.

Being radiant is hard, then?

Being radiant is easy, becoming radiant is hard. The radiant person acts with ease, speaks with ease, and has an easy, welcoming demeanor. Nothing could be easier than being radiant. Just as rain falls freely from the sky, just as the seasons follow in succession, so the radiant person follows and flows along.

Nonetheless, becoming radiant is hard. The path of radiance involves preparation, education, and the cultivation of the salient virtues to the point of their beautiful expression. Along the way, any number of things may go awry.

Conceivably (though about this I’m not sure), one could experience moments of radiance and then ‘fall out’ of them. So that being radiant is easy, but maintaining radiant living–under certain circumstances, in a certain environment, or around certain company–could be hard.

Being radiant is easy, becoming radiant is hard, and maintaining a life of radiance may be hard?

The last qualification seems key. It seems to me that certain environments are conducive to becoming radiant and to maintaining radiance. Benedictine monasteries, Buddhist ashrams, Epicurean communes, Plotinus’s imagined Platonopolis, Japanese gardens, Daoist mountainscapes, the Athenian agora: all of these seem to be environments that are conducive to living a certain way of life. They display natural virtues–e.g., simplicity, directness–in a beautiful way. The natural beauty of the grosbeak, the warbler, and the hummingbird is evident to the eye as well as to the heart.

‘Friendly environments’ may be instrumental for becoming radiant (this claims seems unobjectionable) or may–and here I don’t know–prove necessary. ‘Overly hostile environments’ would not be conducive to the exercise of the salient virtues apart from the exercise of courage, etc. One perceives this clearly when one is walking through Midtown, Soho, or Wall Street during late morning. Then there are any number of vague cases in which certain circumstances, environments, and people neither help nor hinder, neither uplift nor weigh down, neither exemplify nor fail to.

You have been living in the gentle mountains of rural Appalachia and soon will be living in the wooded mountains of northern California?

Yes.