Clauses of Doubting (Quīn / Quōminus)
Verbs and phrases of doubting, hindering, refusing, and delaying — when negated — take a subjunctive clause introduced by quīn. The Latin idiom is sticky: nōn dubitō quīn veniat, "I do not doubt that he is coming." When the verb of hindering is not negated, Latin uses quōminus (= ut eō minus) instead.
quīn = "that" (after non-doubt) or "from" (after non-hindrance); quōminus = "from" — the negated head licenses the construction.
Negation is the trigger. Without it, dubitō + indirect question (dubitō num veniat, "I'm not sure whether he's coming"). With nōn, the construction switches to quīn + subj.
See It In Action
— B. G. i. 4
Caesar on the death of Orgetorix. neque abest suspīciō is an implicit negative — "the suspicion is not absent." That negation licenses quīn + subj. The cōnscīverit (perfect subjunctive) follows sequence rules off the present abest.
— B. G. v. 55
A&G's textbook example of the non-doubting sense — Caesar uses quīn after a negated verb of delay / omission. nūllum tempus intermīsērunt quīn ... literally = "they let no time pass without ...". The English idiom "without -ing" captures it; literal "from" works too.
dubitō without negation reaches for num (indirect question); nōn dubitō reaches for quīn. Same verb, different syntactic license.
verb is negated — "I do not doubt that ..." (assertion of certainty)
nōn dubitō quīn veniat
"I have no doubt that he is coming"
verb is not negated — "I doubt / wonder whether ..." (genuine uncertainty)
dubitō num venturus sit
"I doubt whether he will come"
Tip: The presence or absence of nōn (or neque, haud, etc.) decides the construction. nōn dubitō is an assertion of certainty — the speaker knows it's true. dubitō without negation is genuine doubt — and Latin treats it as an indirect question.
In neque abest suspīciō quīn ipse sibi mortem cōnscīverit, what licenses the quīn + subj. construction?
Study Tips
- •The trigger is negation. nōn dubitō, nōn est dubium, neque cōnstat, haud abest, paulum āfuit — the nōn / neque / haud makes quīn available. Without negation, dubitō takes an indirect question (dubitō num...) instead.
- •Translate quīn in this construction as "that" (with nōn dubitō) or "from" (with verbs of hindering): nōn dubitō quīn veniat "I do not doubt that he is coming"; nōn potest quīn videat "he cannot help but see" (literally "cannot keep from seeing").
- •quōminus (one word, written quōminus or quō minus) appears with non-negated hindering verbs: prohibet quōminus veniat "he prevents him from coming." Caesar uses both quīn and quōminus freely.
- •A subset of expressions takes quīn even without explicit negation when the implied sense is negative: paulum āfuit quīn caperētur "he was within an inch of being captured" (from "little was lacking" — implicitly a negation).