Laudator Temporis Acti

Polybius 12.27.4-6 (tr. Ian Scott-Kilvert):

[4] You can busy yourself among books with very little danger or hardship, provided only that you have taken care to have access to a city which is well supplied with records or to have a library close at hand. [5] After that you need only pursue your researches while reclining on your couch, and you can compare the mistakes of earlier historians without undergoing any hardship. [6] Personal investigation, on the other hand, demands much greater exertion and expense, but it is of prime importance and makes the greatest contribution of all to history.

[4] τὰ μὲν ἐκ τῶν βυβλίων δύναται πολυπραγμονεῖσθαι χωρὶς κινδύνου καὶ κακοπαθείας, ἐάν τις αὐτὸ τοῦτο προνοηθῇ μόνον ὥστε λαβεῖν ἢ πόλιν ἔχουσαν ὑπομνημάτων πλῆθος ἢ βυβλιοθήκην που γειτνιῶσαν. [5] λοιπὸν κατακείμενον ἐρευνᾶν δεῖ τὸ ζητούμενον καὶ συγκρίνειν τὰς τῶν προγεγονότων συγγραφέων ἀγνοίας ἄνευ πάσης κακοπαθείας. [6] ἡ δὲ πολυπραγμοσύνη πολλῆς μὲν προσδεῖται ταλαιπωρίας καὶ δαπάνης, μέγα δέ τι συμβάλλεται καὶ μέγιστόν ἐστι μέρος τῆς ἱστορίας.

Günter Glockmann and Hadwig Helms, Polybios-Lexikon, Bd. II, Lieferung 2 (Berlin: Akademie Verlag, 2005), col. 501 (s.v. πολυπραγμοσύνη):