Plato, Laws 862a

ἑκουσίων—σκοπεῖσθε δὲ εἴτε τι λέγω λέγων ἃ μέλλω λέγειν, εἴτε καὶ μηδὲν τὸ παράπαν. οὐ γάρ φημι ἔγωγε, ὦ Κλεινία καὶ Μέγιλλε, εἴ τίς τινά τι πημαίνει μὴ βουλόμενος ἀλλʼ ἄκων, ἀδικεῖν μέν, ἄκοντα μήν, καὶ ταύτῃ μὲν δὴ νομοθετήσω, τοῦτο ὡς ἀκούσιον ἀδίκημα νομοθετῶν, ἀλλʼ οὐδὲ ἀδικίαν τὸ παράπαν θήσω τὴν τοιαύτην βλάβην, οὔτε ἂν μείζων οὔτε ἂν ἐλάττων τῳ γίγνηται· πολλάκις δὲ ὠφελίαν οὐκ ὀρθὴν γενομένην τὸν τῆς ὠφελίας αἴτιον ἀδικεῖν φήσομεν, ἐὰν ἥ γʼ

but consider whether in saying what I am now going to say I am speaking sense or absolute nonsense. For what I assert, Megillus and Clinias, is not that, if one man harms another involuntarily and without wishing it, he acts unjustly though involuntarily, nor shall I legislate in this way, pronouncing this to be an involuntary act of injustice, but I will pronounce that such an injury is not an injustice at all, whether it be a greater injury or a less. And, if my view prevails, we shall often say that the author of a benefit wrongly done commits an injustice;