I can see no evidence of "tacite" meaning "quietly" rather than literally "silently", so surely this sentence means that we speak, as it were, "without words", and cannot be taken to mean "at a low volume", which could instead be rendered as "tranquille", "placide", "parva voce", etc.
I think I agree. Tacite has 2 meanings:
- in secret. (not speaking of something, to shut up something)
- without a noise, in silent (not quietly)
Tacite gave French "tacite" meaning something that is not said, or implicit, unwritten, assumed, and borrowed in English in "tacit", same meaning.
Looking up in dictionaries give unspoken, etc, as the first meaning for "tacite". I think it's not the first meaning etymologically & historically, but it's the main & most common meaning.
Quietly: with few noises, = allowing speaking quietly
But talking tacite (in silent) is hard!
I've found a "quasi tacite loquere" (almost silently) in texts, and also a "Loquor tacite ne alii me audient" (I am speaking in silence, lest that others will hear me)
Lewis & Short gives "that does not speak, not uttering a sound, silent, still, quiet, noiseless, mute: quod boni est, id tacitus taceas tute tecum et gaudeas" (...)
"per tacitum nemus ire", still, silent, quiet,
In Gaffiot and L&S no example or definition for "quiet" with the meaning of "very few noises" as in "low voices". Olivetti gives as the first meaning "without speaking, silently".
The confusion comes from the fact "quiet" has several meanings in English (calm/with few noises).
: Tăcĭta = Muta, the goddess of Silence.
So, a better translation for this sentence would probably be "We speak in secret" (or even tacitly/implicitly).