§9.9ὅτι δὲ καὶ βελτίων καὶ τιμιωτέρα τῆς σπουδαίας δυνάμεως ἡ ἐνέργεια, ἐκ τῶνδε δῆλον.
That the actuality is also better and more valuable than the good potentiality is clear from the following.
ὅσα γὰρ κατὰ τὸ δύνασθαι λέγεται, ταὐτόν ἐστι δυνατὸν τἀναντία, οἷον τὸ δύνασθαι λεγόμενον ὑγιαίνειν ταὐτόν ἐστι καὶ τὸ νοσεῖν, καὶ ἅμα· ἡ αὐτὴ γὰρ δύναμις τοῦ ὑγιαίνειν καὶ κάμνειν, καὶ ἠρεμεῖν καὶ κινεῖσθαι, καὶ οἰκοδομεῖν καὶ καταβάλλειν, καὶ οἰκοδομεῖσθαι καὶ καταπίπτειν.
For all things that are said to be capable, the same thing is capable of contraries; for instance, that which is said to be capable of being healthy is the same as that which is capable of being sick, and at the same time; for the same potentiality is of being healthy and of being sick, of being at rest and of being moved, of building and of pulling down, and of being built and of falling down.
τὸ μὲν οὖν δύνασθαι τἀναντία ἅμα ὑπάρχει· τὰ δʼ ἐναντία ἅμα ἀδύνατον, καὶ τὰς ἐνεργείας δὲ ἅμα ἀδύνατον ὑπάρχειν (οἷον ὑγιαίνειν καὶ κάμνειν), ὥστʼ ἀνάγκη τούτων θάτερον εἶναι τἀγαθόν, τὸ δὲ δύνασθαι ὁμοίως ἀμφότερον ἢ οὐδέτερον· ἡ ἄρα ἐνέργεια βελτίων.
Now, to be capable of contraries belongs to a thing at the same time; but the contraries cannot exist at the same time, nor can their actualities exist at the same time (for instance, being healthy and being sick). Therefore, one of these actualities must be the good, whereas the potentiality is equally for both or for neither; therefore the actuality is better.
ἀνάγκη δὲ καὶ ἐπὶ τῶν κακῶν τὸ τέλος καὶ τὴν ἐνέργειαν εἶναι χεῖρον τῆς δυνάμεως· τὸ γὰρ δυνάμενον ταὐτὸ ἄμφω τἀναντία.
And in the case of bad things, the end and the actuality must be worse than the potentiality; for that which is capable is the same for both contraries.
δῆλον ἄρα ὅτι οὐκ ἔστι τὸ κακὸν παρὰ τὰ πράγματα· ὕστερον γὰρ τῇ φύσει τὸ κακὸν τῆς δυνάμεως.
It is clear, then, that evil does not exist apart from actual things; for evil is by nature posterior to potentiality.
οὐκ ἄρα οὐδʼ ἐν τοῖς ἐξ ἀρχῆς καὶ τοῖς ἀϊδίοις οὐθὲν ἔστιν οὔτε κακὸν οὔτε ἁμάρτημα οὔτε διεφθαρμένον (καὶ γὰρ ἡ διαφθορὰ τῶν κακῶν ἐστίν).
Therefore, neither in primary principles nor in eternal things is there anything evil or any error or anything damaged (for damage too is of the nature of evil).
εὑρίσκεται δὲ καὶ τὰ διαγράμματα ἐνεργείᾳ· διαιροῦντες γὰρ εὑρίσκουσιν.
Geometrical diagrams are also discovered by an activity; for they discover them by dividing them.
εἰ δʼ ἦν διῃρημένα, φανερὰ ἂν ἦν· νῦν δʼ ἐνυπάρχει δυνάμει.
If they had already been divided, they would have been obvious; but as it is, they are present potentially.
διὰ τί δύο ὀρθαὶ τὸ τρίγωνον;
Why is the triangle equal to two right angles?
ὅτι αἱ περὶ μίαν στιγμὴν γωνίαι ἴσαι δύο ὀρθαῖς.
Because the angles about one point are equal to two right angles.
εἰ οὖν ἀνῆκτο ἡ παρὰ τὴν πλευράν, ἰδόντι ἂν ἦν εὐθὺς δῆλον διὰ τί.
If, then, the line parallel to the side had been drawn up, it would have been straightway obvious to anyone who saw it why this is so.
ἐν ἡμικυκλίῳ ὀρθὴ καθόλου διὰ τί;
Why is the angle in a semicircle universally a right angle?
ἐὰν ἴσαι τρεῖς, ἥ τε βάσις δύο καὶ ἡ ἐκ μέσου ἐπισταθεῖσα ὀρθή, ἰδόντι δῆλον τῷ ἐκεῖνο εἰδότι.
If three lines are equal, namely the two parts of the base and the one erected upright from the center, it is obvious to anyone who sees it, provided they know that premise.
ὥστε φανερὸν ὅτι τὰ δυνάμει ὄντα εἰς ἐνέργειαν ἀγόμενα εὑρίσκεται· αἴτιον δὲ ὅτι ἡ νόησις ἐνέργεια· ὥστʼ ἐξ ἐνεργείας ἡ δύναμις, καὶ διὰ τοῦτο ποιοῦντες γιγνώσκουσιν (ὕστερον γὰρ γενέσει ἡ ἐνέργεια ἡ κατʼ ἀριθμόν).
So it is clear that potentially existing things are discovered by being brought into actuality; and the reason is that thinking is an actuality; so that potentiality comes from actuality, and for this reason they know by doing (for the individual actuality is posterior in generation).