§2.1.2Ἐπίστασθαι δὲ οἰόμεθʼ ἕκαστον ἁπλῶς, ἀλλὰ μὴ τὸν σοφιστικὸν τρόπον τὸν κατὰ συμβεβηκός, ὅταν τήν τʼ αἰτίαν οἰώμεθα γινώσκειν διʼ ἥν τὸ πρᾶγμά ἐστιν, ὅτι ἐκείνου αἰτία ἐστί, καὶ μὴ ἐνδέχεσθαι τοῦτʼ ἄλλως ἔχειν.
And we think we know each thing unqualifiedly, and not in the sophistical manner which is accidental, when we think we know the cause because of which the thing is, namely, that it is the cause of that thing, and that it is not possible for this to be otherwise.
δῆλον τοίνυν ὅτι τοιοῦτόν τι τὸ ἐπίστασθαί ἐστι· καὶ γὰρ οἱ μὴ ἐπιστάμενοι καὶ οἱ ἐπιστάμενοι οἱ μὲν οἴονται αὐτοὶ οὕτως ἔχειν, οἱ δʼ ἐπιστάμενοι καὶ ἔχουσιν, ὥστε οὗ ἀπλῶς ἔστιν ἐπιστήμη, τοῦτʼ ἀδύνατον ἄλλως ἔχειν.
It is clear, then, that knowing is something of this sort; for both those who do not know and those who know, the former think they themselves are in this state, while those who know actually are, so that that of which there is unqualified knowledge, this is impossible to be otherwise.
Εἰ μὲν οὖν καὶ ἕτερος ἔστι τοῦ ἐπίστασθαι τρόπος, ὕστερον ἐροῦμεν, φαμὲν δὲ καὶ διʼ ἀποδείξεως εἰδέναι.
Now, whether there is also another manner of knowing, we shall say later; but we say that we also know through demonstration.
ἀπόδειξιν δὲ λέγω συλλογισμὸν ἐπιστημονικόν· ἐπιστημονικὸν δὲ λέγω καθʼ ὅν τῷ ἔχειν αὐτὸν ἐπιστάμεθα.
And by demonstration I mean a scientific deduction; and by scientific I mean that in virtue of having which we know.
εἰ τοίνυν ἐστὶ τὸ ἐπίστασθαι οἷον ἔθεμεν, ἀνάγκη καὶ τὴν ἀποδεικτικὴν ἐπιστήμην ἐξ ἀληθῶν τʼ εἶναι καὶ πρώτων καὶ ἀμέσων καὶ γνωριμωτέρων καὶ προτέρων καὶ αἰτίων τοῦ συμπεράσματος· οὕτω γὰρ ἔσονται καὶ αἱ ἀρχαὶ οἰκεῖαι τοῦ δεικνυμένου.
If, then, knowing is as we have posited, it is necessary that demonstrative knowledge is also from things that are true, first, immediate, more known, prior to, and causes of the conclusion; for in this way the starting-points will also be appropriate to what is shown.
συλλογισμὸς μὲν γὰρ ἔσται καὶ ἄνευ τούτων, ἀπόδειξις δʼ οὐκ ἔσται· οὐ γὰρ ποιήσει ἐπιστήμην.
For a deduction will exist even without these, but a demonstration will not; for it will not produce knowledge.
ἀληθῆ μὲν οὖν δεῖ εἶναι, ὅτι οὐκ ἔστι τὸ μὴ ὄν ἐπίστασθαι, οἷον ὅτι ἡ διάμετρος σύμμετρος.
It is necessary, then, that they are true, because it is not possible to know that which is not, for instance, that the diagonal is commensurable.
ἐκ πρώτων δʼ ἀναποδείκτων, ὅτι οὐκ ἐπιστήσεται μὴ ἔχων ἀπόδειξιν αὐτῶν· τὸ γὰρ ἐπίστασθαι ὧν ἀπόδειξις ἔστι μὴ κατὰ συμβεβηκός, τὸ ἔχειν ἀπόδειξίν ἐστιν.
And they must be from first indemonstrable things, because one will not know them if one does not have a demonstration of them; for to know those things of which there is a demonstration, not accidentally, is to have a demonstration of them.
αἴτιά τε καὶ γνωριμώτερα δεῖ εἶναι καὶ πρότερα, αἴτια μὲν ὅτι τότε ἐπιστάμεθα ὅταν τὴν αἰτίαν εἰδῶμεν, καὶ πρότερα, εἴπερ αἴτια, καὶ προγινωσκόμενα οὐ μόνον τὸν ἕτερον τρόπον τῷ ξυνιέναι, ἀλλὰ καὶ τῷ εἰδέναι ὅτι ἔστιν.
And they must be causes, more known, and prior: causes because we know then when we know the cause; and prior, if indeed they are causes, and previously known not only in the other manner by understanding, but also by knowing that they exist.
πρότερα δʼ ἐστὶ καὶ γνωριμώτερα διχῶς· οὐ γὰρ ταὐτὸν πρότερον τῇ φύσει καὶ πρὸς ἡμᾶς πρότερον, οὐδὲ γνωριμώτερον καὶ ἡμῖν γνωριμώτερον.
But things are prior and more known in two ways; for what is prior by nature and what is prior to us are not the same, nor is what is more known and what is more known to us the same.
λέγω δὲ πρὸς ἡμᾶς μὲν πρότερα καὶ γνωριμώτερα τὰ ἐγγύτερον τῆς αἰσθήσεως, ἀπλῶς δὲ πρότερα καὶ γνωριμώτερα τὰ πορρώτερον.
And I call prior and more known to us the things that are nearer to perception, and unqualifiedly prior and more known the things that are further away.
ἔστι δὲ πορρωτάτω μὲν τὰ καθόλου μάλιστα, ἐγγυτάτω δὲ τὰ καθʼ ἕκαστα· καὶ ἀντίκειται ταῦτʼ ἀλλήλοις.
And furthest away are the things that are most universal, and nearest are the particulars; and these are opposite to each other.
ἐκ πρώτων δʼ ἐστὶ τὸ ἐξ ἀρχῶν οἰκείων· ταὐτὸ γὰρ λέγω πρῶτον καὶ ἀρχήν.
And to be from first things is to be from appropriate starting-points; for I call the same thing first and starting-point.
ἀρχὴ δʼ ἐστὶν ἀποδείξεως πρότασις ἄμεσος, ἄμεσος δὲ ἧς μὴ ἔστιν ἄλλη προτέρα.
And a starting-point of a demonstration is an immediate premise, and immediate is that than which there is no other prior.
πρότασις δʼ ἐστὶν ἀποφάνσεως τὸ ἕτερον μόριον, ἓν καθʼ ἑνός, διαλεκτικὴ μὲν ἡ ὁμοίως λαμβάνουσα ὁποτερονοῦν, ἀποδεικτικὴ δὲ ἡ ὡρισμένως θάτερον, ὅτι ἀληθές.
And a premise is one part of an assertion, one thing of one thing; dialectical is that which assumes either part indifferently, and demonstrative is that which determinately assumes one of them as true.
ἀπόφανσις δὲ ἀντιφάσεως ὁποτερονοῦν μόριον, ἀντίφασις δὲ ἀντίθεσις ἧς οὐκ ἔστι μεταξὺ καθ᾿ αὑτήν, μόριον δʼ ἀντιφάσεως τὸ μὲν τὶ κατὰ τινὸς κατάφασις, τὸ δὲ τὶ ἀπὸ τινὸς ἀπόφασις.
And an assertion is either part of a contradiction, and a contradiction is an opposition which has no middle in itself; and the part of a contradiction which asserts something of something is an affirmation, and that which denies something of something is a negation.
Ἀμέσου δʼ ἀρχῆς συλλογιστικῆς θέσιν μὲν λέγω ἣν μὴ ἔστι δεῖξαι, μηδʼ ἀνάγκη ἔχειν τὸν μαθησόμενόν τι· ἣν δʼ ἀνάγκη ἔχειν τὸν ὁτιοῦν μαθησόμενον, ἀξίωμα· ἔστι γὰρ ἔνια τοιαῦτα· τοῦτο γὰρ μάλιστʼ ἐπὶ τοῖς τοιούτοις εἰώθαμεν ὄνομα λέγειν.
Of an immediate deductive starting-point, that which cannot be proved, and which it is not necessary for one who is to learn anything to possess, I call a thesis; but that which it is necessary for anyone who is to learn anything whatever to possess, I call an axiom; for there are some such things, and this is the name we are most accustomed to use for such cases.
θέσεως δʼ ἡ μὲν ὁποτερονοῦν τῶν μορίων τῆς ἀντιφάσεως λαμβάνουσα, οἷον λέγω τὸ εἶναί τι ἢ τὸ μὴ εἶναί τι, ὑπόθεσις, ἡ δʼ ἄνευ τούτου ὁρισμός.
And of a thesis, that which assumes either of the parts of a contradiction, for instance, I mean that something is or that something is not, is a hypothesis, and that without this is a definition.
ὁ γὰρ ὁρισμός θέσις μέν ἐστι· τίθεται γὰρ ὁ ἀριθμητικός μονάδα τὸ ἀδιαίρετον εἶναι κατὰ τὸ ποσόν· ὑπόθεσις δʼ οὐκ ἔστι· τὸ γὰρ τί ἐστι μονὰς καὶ τὸ εἶναι μονάδα οὐ ταὐτόν.
For a definition is indeed a thesis; for the arithmetician posits that a unit is that which is indivisible in respect of quantity; but it is not a hypothesis; for what a unit is and that a unit exists are not the same.
Ἐπεὶ δὲ δεῖ πιστεύειν τε καὶ εἰδέναι τὸ πρᾶγμα τῷ τοιοῦτον ἔχειν συλλογισμὸν ὃν καλοῦμεν ἀπόδειξιν, ἔστι δʼ οὗτος τῷ ταδὶ εἶναι ἐξ ὧν ὁ συλλογισμός, ἀνάγκη μὴ μόνον προγινώσκειν τὰ πρῶτα, ἢ πάντα ἢ ἔνια, ἀλλὰ καὶ μᾶλλον· αἰεὶ γὰρ διʼ ὃ ὑπάρχει ἕκαστον, ἐκείνῳ μᾶλλον ὑπάρχει, οἷον διʼ ὃ φιλοῦμεν, ἐκεῖνο φίλον μᾶλλον.
And since one must believe in and know the thing by having such a deduction which we call a demonstration, and this is so by these things being so from which the deduction is made, it is necessary not only to have prior knowledge of the first things, either all or some, but also to have it more; for that because of which each thing holds, always holds more to that thing, for instance, that because of which we love is more loved.
ὥστʼ εἴπερ ἴσμεν διὰ τὰ πρῶτα καὶ πιστεύομεν, κἀκεῖνα ἴσμεν τε καὶ πιστεύομεν μᾶλλον, ὅτι διʼ ἐκεῖνα καὶ τὰ ὕστερα.
So if we know and believe through the first things, we also know and believe those first things more, because through them we also know the subsequent things.
οὐχ οἷόν τε δὲ πιστεύειν μᾶλλον ὧν οἶδεν ἃ μὴ τυγχάνει μήτε εἰδὼς μήτε βέλτιον διακείμενος ἢ εἰ ἐτύγχανεν εἰδώς.
But it is not possible to believe more in those things which one does not happen either to know or to be in a better state than if one actually knew them, than in the things which one knows.
συμβήσεται δὲ τοῦτο, εἰ μή τις προγνώσεται τῶν διʼ ἀπόδειξιν πιστευόντων· μᾶλλον γὰρ ἀνάγκη πιστεύειν ταῖς ἀρχαῖς ἢ πάσαις ἢ τισὶ τοῦ συμτπεράσματος.
And this will happen if one who believes through demonstration does not have prior knowledge; for it is necessary to believe more in the starting-points, either all or some, than in the conclusion.
τὸν δὲ μέλλοντα ἕξειν τὴν ἐπιστήμην τὴν διʼ ἀποδείξεως οὐ μόνον δεῖ τὰς ἀρχὰς μᾶλλον γνωρίζειν καὶ μᾶλλον αὐταῖς πιστεύειν ἢ τῷ δεικνυμένῳ, ἀλλὰ μηδʼ ἄλλο αὐτῷ πιστότερον εἶναι μηδὲ γνωριμώτερον τῶν ἀντικειμένων ταῖς ἀρχαῖς ἐξ ὧν ἔσται συλλογισμὸς ὁ τῆς ἐναντίας ἀπάτης, εἴπερ δεῖ τὸν ἐπιστάμενον ἁπλῶς ἀμετάπειστον εἶναι.
And one who is to have the knowledge which is through demonstration must not only know the starting-points more and believe in them more than in what is shown, but also nothing else must be more credible or more known to him among the opposites of the starting-points from which there will be a deduction of the contrary error, if indeed one who knows unqualifiedly must be unshakeable.