You can see how infinitely laborious and fruitless it would be to try to refute every objection they offer, when they have resolved never to think before they speak provided that somehow or other they contradict our arguments.

[Quorum dicta contraria si totiens uelimus refellere, quotiens obnixa fronte statuerint non cogitare quid dicant, dum quocumque modo nostris disputationibus contradicant, quam sit infinitum et aerumnosum et infructuosum uides.]

Augustine of Hippo (354-430) Christian church father, philosopher, saint [b. Aurelius Augustinus]

City of God [De Civitate Dei], Book 2, ch. 1 (2.1) (AD 412-416) [tr. Bettenson (1972)]
    (Source)

(Source (Latin)). Alternate translations:

If we should bind ourselves to give an answer to every contradiction that their impudence will thrust forth (how falsely they care not, for they do but make a show of opposition into our assertions), you see what a trouble it would be, how endless, and how fruitless.
[tr. Healey (1610)]

Now, if we were to propose to confute their objections as often as they with brazen face chose to disregard our arguments, and so often as they could by any means contradict our statements, you see how endless, and fruitless, and painful a task we should be undertaking.
[tr. Dods (1871)]

You can easily see what an endless, wearisome, and fruitless task it would be, if I were to refute all the unconsidered objections of people who pig-headedly contradict everything I say.
[tr. Zema/Walsh (1950)]

If we were bound to refute their objections every time they make their bull-headed resolve not to consider the meaning of their words as long as they deny our arguments, no matter how, you see how endless and wearisome and unprofitable it would be.
[tr. McCracken (Loeb) (1957)]

If we resolved to refute their contrary arguments as often as they resolve obstinately to contradict our reasoning in whatever way they can, without considering the truth of what they say, you see what an infinite and toilsome and fruitless task we should have.
[tr. Dyson (1998)]

So you see how endlessly futile and fruitless it would be if we wanted to refute their objections every time they obstinately resolved not to think through what they say but merely to speak, just so long as they contradict our arguments in any way they can.
[tr. Babcock (2012)]