Cum causal or concessive takes the Subjunctive:— id difficile nōn est, cum tantum equitātū valeāmus (B. C. 3.86) , this is not difficult since we are so strong in cavalry. [Causal.] cum sōlitūdō īnsidiārum et metūs plēna sit , ratiō ipsa monet amīcitiās comparāre (Fin. 1.66) , since solitude is full of treachery and fear, reason itself prompts us to contract friendships. [Causal.] cum prīmī ōrdinēs concidissent , tamen ācerrimē reliquī resistēbant (B. G. 7.62) , though the first ranks had fallen, still the others resisted vigorously. [Concessive.] brevī spatiō legiōnēs numerō hominum explēverat, cum initiō nōn amplius duōbus mīlibus habuisset (Sall. Cat. 56 ), in a short time he had filled out the legions with their complement of men, though at the start he had not had more than two thousand. [Concessive.]

Cum causal may usually be translated by since; cum concessive by although or while; either, occasionally, by when. Cum in these uses is often emphasized by ut , utpote , quippe , praesertim ; as, nec reprehendō : quippe cum ipse istam reprehēnsiōnem nōn fūgerim ( Att. 10.3 A), I find no fault; since I myself did not escape that blame. These causal and concessive uses of cum are of relative origin and are parallel to quī causal and concessive (§ 535 . e ). The attendant circumstances are regarded as the cause of the action, or as tending to hinder it. In early Latin cum ( quom ) causal and concessive usually takes the Indicative: as, quom tua rēs distrahitur , utinam videam (Pl. Trin. 617) , since your property is being torn in pieces , O that I may see , etc.