The English preposition 'without' is a word whose modern meaning has almost entirely replaced its original one. To speakers of Old English, 'wiþūtan' meant 'on the outside of' — a purely spatial term. The modern sense of 'lacking' or 'in the absence of' represents a semantic shift so complete that the original meaning now sounds archaic or poetic.
The word is a compound of two Old English elements: 'wiþ' (against, opposite, toward — the ancestor of modern 'with,' which has itself undergone a dramatic semantic reversal from 'against' to 'together with') and 'ūtan' (from outside, on the outside), derived from 'ūt' (out, from Proto-Germanic *ūt). The compound 'wiþūtan' thus meant something like 'against the outside' or 'on the outer side,' a purely spatial designation.
In Old English, 'wiþūtan' contrasted neatly with 'wiþinnan' (within, on the inside). The pair formed a clean spatial opposition: 'wiþinnan þǣm wealle' meant 'within the wall' and 'wiþūtan þǣm wealle' meant 'outside the wall.' This spatial sense persisted well into the Early Modern period and can still be found in Shakespeare: 'Without the gate' in Henry V means 'outside the gate,' not 'lacking the gate.'
The semantic shift from 'outside' to 'lacking' occurred gradually during the Middle English period, roughly the thirteenth and fourteenth centuries. The conceptual bridge is not difficult to see: what is 'outside' a group or collection is 'not included in' it, and what is 'not included' is 'absent' or 'lacking.' This kind of spatial-to-abstract mapping is extremely common in the history of prepositions across languages.
By the fifteenth century, the abstract 'lacking' sense had become dominant, and the spatial 'outside' sense was retreating. Modern English uses 'outside' or 'beyond' where Old English would have used 'wiþūtan.' The spatial sense survives today mainly in deliberately archaic or literary contexts: 'the darkness without' or 'voices without the door.'
Scots English preserves the old spatial meaning more robustly than standard English. The word 'outwith,' meaning 'outside of,' is a standard Scots preposition ('outwith the scope of this document' is common in Scottish legal and administrative English). This word combines 'out' and 'with' in a formation parallel to the original Old English compound, and its continued vitality in Scots shows how differently a language variety can develop when it retains an archaic sense that the standard dialect has lost.
The first element, 'wiþ,' has its own remarkable history. In Old English, 'wiþ' primarily meant 'against' or 'in opposition to' — the opposite of its modern meaning. The shift from 'against' to 'together with' occurred in Middle English, probably through the intermediate sense of 'in exchange with' or 'alongside.' German 'wider' (against)
The second element, 'ūtan,' comes from Proto-Germanic *ūtanō (from outside), built on *ūt (out), from PIE *ūd- (up, out). This root gave English 'out,' 'outer,' 'outward,' 'utmost,' and 'utter' (originally 'outer,' then 'complete, absolute'). Dutch 'buiten' (outside) and German 'außen' (outside) are related but developed differently.
In modern English, 'without' functions primarily as a preposition ('without help'), but it also serves as an adverb ('doing without') and, in archaic or literary English, as a conjunction ('you won't succeed without you try'). This conjunctive use, meaning 'unless,' was standard through the eighteenth century but is now confined to dialects.
The word participates in a number of set phrases and idioms: 'without a doubt,' 'without fail,' 'without further ado,' 'without so much as,' and 'without rhyme or reason.' The last of these is attested from the sixteenth century and was reportedly used by Sir Thomas More when he told a friend that his prose was better, despite lacking poetic form: 'Now it is somewhat, for now it is rhyme; before, it was neither rhyme nor reason.'