Laudator Temporis Acti

Horace, Epistles 1.6.15-16 (tr. Colin Macleod):

The wise will be called mad, the just unjust,
if they go too far in seeking even goodness.

insani sapiens nomen ferat, aequus iniqui,
ultra quam satis est virtutem si petat ipsam.

Augustus S. Wilkins on ultra quam satis est:

There is no reason to suppose (with Macleane) that Horace is speaking either ironically or `with an unusual fit of enthusiasm'. The need of moderation in pursuit even of virtue is a commonplace with philosophers: cp. Cic. pro Mur. 30, 63 nostri illi a Platone et Aristotele, moderati homines et temperati aiunt...omnes virtutes mediocritate quadam esse temperatas. Cic. Tusc. IV. 25, 55 studia vel optimarum rerum sedata tamen et tranquilla esse debent. ib. IV. 29, 62 etiam si virtutis vehementior appetitus sit, eadem est omnibus ad deterrendum adhibenda oratio.

Cf. also ultra quam in Tacitus, Agricola 4 (tr. Herbert W. Benario):

I remember that he used to say that, early in his life, he would have devoted himself too enthusiastically to the study of philosophy, to an extent greater than was fitting for a Roman who was also a member of the senatorial class, had not the wisdom of his mother restrained his eager and excited spirit. Certainly his lofty and talented nature yearned for the beautiful ideal of great and noble glory with greater passion than caution. Soon the discernment of age calmed him down, yet he retained from his contact with philosophy a sense of proportion that is very difficult to acquire.

memoria teneo solitum ipsum narrare se prima in iuventa studium philosophiae acrius, ultra quam concessum Romano ac senatori, hausisse, ni prudentia matris incensum ac flagrantem animum coercuisset. scilicet sublime et erectum ingenium pulchritudinem ac speciem magnae excelsaeque gloriae vehementius quam caute adpetebat. mox mitigavit ratio et aetas, retinuitque, quod est difficillimum, ex sapientia modum.