Plato, Epinomis 978a

ὄντως, οὐκ ἂν ἔτι πᾶς ἄν τις γνοίη σύμπαντα ἀριθμὸν ὅσης ἡμῖν δυνάμεως αἴτιος ἂν εἴη συγγιγνόμενος—ἐπεὶ καὶ τὰ κατὰ μουσικὴν πᾶσαν διαριθμουμένων κινήσεώς τε καὶ φθόγγων δῆλον ὅτι δεῖ—καὶ τὸ μέγιστον, ἀγαθῶν ὡς πάντων αἴτιον, ὅτι δὲ κακῶν οὐδενός, εὖ τοῦτο γνωστέον, ὃ καὶ τάχα γένοιτʼ ἄν. ἀλλʼ ἡ σχεδὸν ἀλόγιστός τε καὶ ἄτακτος ἀσχήμων τε καὶ ἄρρυθμος ἀνάρμοστός τε φορά, καὶ πάνθʼ ὁπόσα κακοῦ

it is not anybody who can tell how great is the power which we owe to the accompaniment of number as a whole—for it is clear that everything in music needs a distinct numeration of movement and notes—and above all, how it is the cause of all good things; and that it is the cause of no evil thing is a point that must be well understood, as it may be quickly enough. Nay, the motion that we may call unreasoned and unordered, lacking shape and rhythm and harmony, and everything that has a share of some evil,