So, I thought I might post a brief spelling or vocabulary lesson. Hermetic (please note the e) means to close tightly, to shut off or seal completely from outside influences. The bag of coffee I have in the pantry waiting to be opened is hermetically sealed. An astronaut who would die if exposed to open space wears a pressure suit that is hermetically sealed. Even someone in a hazmat suit with its own supply of filtered air or oxygen is hermetically protected. My hermitage and I, however, are not. Something that is eremitic (please note the i and the lack of an initial h!) is about desert dwelling from the Greek word ερεμοσ (eremos) for desert or wilderness; it is about stricter separation from the world, and the silence of solitude, not about being insulated from all outside influences which would need to include air, light, love, and God (who does not merely dwell within us).
In this last quality, however, we do come to the closest point of similarity between the two realities; both eremitical and hermetical are ways of dealing with outside influences; they both involve some degree of personal withdrawal or physical separation. Still, while the hermit is diligent about not being or becoming enmeshed in the values, perspectives, and attitudes she considers "worldly" or opposed to Christ (including those dimensions existing within Christ's Church that fit this bill), there are many points of contact between the hermit and the larger world which are embraced for the sake of God's Love and the mercy which frees everyone and everything from bondage to sin and its consequences.In other words, Roman Catholic eremitical life is about the unique form of community we know as solitude; it is not about isolation. (Even recluses live reclusion within a communal and ecclesial context for the sake of community in its many forms.) I am not completely insulated from the world around me; instead, I live the silence of solitude in order to be made more capable of engaging with or encountering the larger world as a citizen of God's Kingdom. Hermits don't live eremetical life (note the e that should be an i) or hermetical solitude, but eremitical life. (N.B., eremetical, as even my inadequate spellchecker reminds me, is not a real word by the way; it is not even an alternate spelling of the correct word!) So, to summarize, if you are speaking about coffee sealed in an airtight and waterproof foil pouch, the appropriate family of words is derived from hermetic. If you are speaking of a hermit who lives the silence of solitude (and so forth), the appropriate words are derived from eremos and include eremite, eremitic, and eremitical. And now I need a cup of coffee!!