'All one' contracted — and its mirror 'atone' is 'at one,' making solitude and reconciliation the same building blocks.
Without anyone or anything else; on one's own; solely.
From Middle English "al one," literally "all one" or "wholly one," a contraction of Old English "eall āna" where "eall" meant "all, entirely" and "āna" meant "one, sole." The Old English "āna" derives from Proto-Germanic *ainaz ("one"), from PIE *h₁óynos ("one, single"), the same root that produced Latin "ūnus" ("one"), Old Irish "óen," Greek "οἴνη" (oínē, "the ace on a die"), and Sanskrit "éka" (with remodeling). The compound "all one" originally meant "wholly by oneself" and was
'Alone' is literally 'all one' — entirely one, wholly by yourself. And 'atone' was originally 'at one' — to become 'at one' with someone, to reconcile. So 'alone' (all one) and 'atone' (at one) are mirror images: being alone is being wholly singular, while atoning is becoming unified again. Even 'only' comes