Laudator Temporis Acti

Sallust, Jugurthine War 53.8 (tr. J.C. Rolfe):

Thereupon in place of fear a sudden joy arose. The exultant soldiers called out to one another, told of their exploits and heard the tales of others. Each man praised his own valiant deeds to the skies. For so it is with human affairs; in time of victory the very cowards may brag, while defeat discredits even the brave.

igitur pro metu repente gaudium exortum, milites alius alium laeti appellant, acta edocent atque audiunt, sua quisque fortia facta ad caelum fert. quippe res humanae ita sese habent: in victoria vel ignavis gloriari licet, advorsae res etiam bonos detrectant.

exortum codd.: mutatur Priscian (Grammatici Latini 3.296.7)

Prisciani Caesariensis Ars, Liber XVIII, Pars Altera, 2: Commento a cura di Elena Spangenberg Yanes (Hildesheim: Weidmann, 2017), p. 109:

In Sall. Iug. 53, 8 la variante priscianea mutatur per exortum dei codici sallustianni appare una lectio difficilior ed è sostenuta dal confronto con Iug. 83, 1 incerta pro certis mutare (vd. Koestermann 1971, p. 213). Ernout, Kurfess e Reynolds mettono a testo mutatur. Nitzschner 1884, pp. 96-97, ritiene, invece, che si tratti di un errore di memoria del grammatico.

Leighton D. Reynolds, "Experiences of an Editor of Classical Latin Texts," Revue d'histoire des textes 30 (2000) 1-15 (at 13):

I do not see how it is possible to form any general policy with regard to the ancient evidence. The ancient variant is sometimes right, sometimes wrong, and each case must be judged on its merits and by the normal methods of textual criticism. There is a tendency to overvalue such 'venerable' variants; but, when one comes to think of it, the medieval tradition which has given us such a good text of Sallust must be full of venerable readings too.

I shall give just two examples:

Iug. 53.8 Igitur pro metu repente gaudium mutatur: milites alius alium laeti appellant.

mutatur Priscianus: exortum ω

The Romans suddenly realized that the troops approaching in the darkness were not the enemy, but their own comrades, and fear turned to joy. Priscian is quoting this passage precisely to illustrate the use of mutare pro. mutare fell out before milites through homoearcton and was replaced by the obvious stopgap exortum.