A man who does not see this is senseless; he who does see it, and still advocates such a measure, is impious.

[Hoc qui non videt, excors; qui, cum videt, decernit, impius est.]

Marcus Tullius Cicero (106-43 BC) Roman orator, statesman, philosopher

Philippics [Philippicae; Antonian Orations], No. 5, ch. 2 / sec. 5 (5.2/5.5) (43-01-01 BC) [tr. Yonge (1903)]
    (Source)

On the suggestion that Mark Antony be bought off by giving him governorship of Transalpine Gaul, and how that would merely give him more troops and power to move against Rome.

(Source (Latin)). Other translations:

He that does not see this is a fool; he that sees it, and proposes it, is disloyal.
[tr. Ker (Loeb) (1926)]

Anyone who does not see this is a fool; anyone who does and makes the proposal all the same is treacherous.
[tr. Manuwald (2007)]

Who does not see this is senseless; who sees and still approves is ungodly.
[E.g.]