Humanitext Reader

Plato · Timaeus §54-55

Construction of the Regular Solids and the Elements

Passage 21 of 41 · Greek

Summary

The square and the equilateral triangle are constructed from the basic right-angled triangles to form the regular solids representing fire, air, water, and earth. It is explained that the fifth solid is used for the universe, and earth is assigned the most stable cubic form.

§54ΤΙ. τοῖν δὴ δυοῖν τριγώνοιν τὸ μὲν ἰσοσκελὲς μίαν εἴληχεν φύσιν, τὸ δὲ πρόμηκες ἀπεράντους· προαιρετέον οὖν αὖ τῶν ἀπείρων τὸ κάλλιστον, εἰ μέλλομεν ἄρξεσθαι κατὰ τρόπον.
TI. Now, of the two triangles, the isosceles has obtained a single nature, while the scalene (oblong) has infinite natures; we must therefore again select the most beautiful from these infinite ones, if we are to begin in the proper manner.
ἂν οὖν τις ἔχῃ κάλλιον ἐκλεξάμενος εἰπεῖν εἰς τὴν τούτων σύστασιν, ἐκεῖνος οὐκ ἐχθρὸς ὢν ἀλλὰ φίλος κρατεῖ·
If, then, anyone is able to select and speak of a more beautiful one for the construction of these, he, being not an enemy but a friend, wins the day.
τιθέμεθα δʼ οὖν τῶν πολλῶν τριγώνων κάλλιστον ἕν, ὑπερβάντες τἆλλα, ἐξ οὗ τὸ ἰσόπλευρον τρίγωνον ἐκ τρίτου συνέστηκεν.
At any rate, bypassing the others, we hypothesize as the most beautiful one among the many triangles that single one from which the equilateral triangle is constructed as a third.
διότι δέ, λόγος πλείων· ἀλλὰ τῷ τοῦτο ἐλέγξαντι καὶ ἀνευρόντι δὴ οὕτως ἔχον κεῖται φίλια τὰ ἆθλα.
The reason why is a longer story; but for him who refutes this and finds that it is indeed so, friendly prizes lie in store.
προῃρήσθω δὴ δύο τρίγωνα ἐξ ὧν τό τε τοῦ πυρὸς καὶ τὰ τῶν ἄλλων σώματα μεμηχάνηται, τὸ μὲν ἰσοσκελές, τὸ δὲ τριπλῆν κατὰ δύναμιν ἔχον τῆς ἐλάττονος τὴν μείζω πλευρὰν ἀεί.
Let there be selected, then, two triangles from which the body of fire and those of the other bodies have been crafted: the one being the isosceles, the other being that which always has the square of its longer side three times that of the shorter side.
τὸ δὴ πρόσθεν ἀσαφῶς ῥηθὲν νῦν μᾶλλον διοριστέον.
Now, what was previously stated obscurely must now be more clearly defined.
τὰ γὰρ τέτταρα γένη διʼ ἀλλήλων εἰς ἄλληλα ἐφαίνετο πάντα γένεσιν ἔχειν, οὐκ ὀρθῶς φανταζόμενα·
For the four classes appeared to have their generation all through one another into one another, but this appearance was incorrect.
γίγνεται μὲν γὰρ ἐκ τῶν τριγώνων ὧν προῃρήμεθα γένη τέτταρα, τρία μὲν ἐξ ἑνὸς τοῦ τὰς πλευρὰς ἀνίσους ἔχοντος, τὸ δὲ τέταρτον ἓν μόνον ἐκ τοῦ ἰσοσκελοῦς τριγώνου συναρμοσθέν.
For from the triangles we have selected, four classes are generated: three of them from the one having unequal sides, and the fourth one alone assembled from the isosceles triangle.
οὔκουν δυνατὰ πάντα εἰς ἄλληλα διαλυόμενα ἐκ πολλῶν σμικρῶν ὀλίγα μεγάλα καὶ τοὐναντίον γίγνεσθαι, τὰ δὲ τρία οἷόν τε·
Therefore, it is not possible for all of them, when dissolved into one another, to become a few large ones from many small ones, and vice versa; but for the three, this is possible.
ἐκ γὰρ ἑνὸς ἅπαντα πεφυκότα λυθέντων τε τῶν μειζόνων πολλὰ σμικρὰ ἐκ τῶν αὐτῶν συστήσεται, δεχόμενα τὰ προσήκοντα ἑαυτοῖς σχήματα, καὶ σμικρὰ ὅταν αὖ πολλὰ κατὰ τὰ τρίγωνα διασπαρῇ, γενόμενος εἷς ἀριθμὸς ἑνὸς ὄγκου μέγα ἀποτελέσειεν ἂν ἄλλο εἶδος ἕν.
For since they are all naturally born from one, when the larger ones are dissolved, many small ones will be constructed from the same elements, receiving the shapes appropriate to them; and conversely, when many small ones are dispersed into their triangles, they might, by becoming a single number of one bulk, complete another single large form.
ταῦτα μὲν οὖν λελέχθω περὶ τῆς εἰς ἄλληλα γενέσεως· οἷον δὲ ἕκαστον αὐτῶν γέγονεν εἶδος καὶ ἐξ ὅσων συμπεσόντων ἀριθμῶν, λέγειν ἂν ἑπόμενον εἴη.
So let this be said concerning their generation into one another; and it would follow next to state what sort of form each of them has become, and from the combination of what numbers.
ἄρξει δὴ τό τε πρῶτον εἶδος καὶ σμικρότατον συνιστάμενον, στοιχεῖον δʼ αὐτοῦ τὸ τὴν ὑποτείνουσαν τῆς ἐλάττονος πλευρᾶς διπλασίαν ἔχον μήκει·
The first and smallest form to be constructed will lead the way, and its element is that triangle which has its hypotenuse twice the length of its shorter side.
σύνδυο δὲ τοιούτων κατὰ διάμετρον συντιθεμένων καὶ τρὶς τούτου γενομένου, τὰς διαμέτρους καὶ τὰς βραχείας πλευρὰς εἰς ταὐτὸν ὡς κέντρον ἐρεισάντων, ἓν ἰσόπλευρον τρίγωνον ἐξ ἓξ τὸν ἀριθμὸν ὄντων γέγονεν.
When two of these are put together diagonally, and this is done three times, by fixing their diagonals and shorter sides at the same point as a center, a single equilateral triangle is formed out of six in number.
§55ΤΙ. τρίγωνα δὲ ἰσόπλευρα συνιστάμενα τέτταρα κατὰ σύντρεις ἐπιπέδους γωνίας μίαν στερεὰν γωνίαν ποιεῖ, τῆς ἀμβλυτάτης τῶν ἐπιπέδων γωνιῶν ἐφεξῆς γεγονυῖαν·
TI. And four equilateral triangles, when put together so that three plane angles meet, form a single solid angle, which is formed next after the most obtuse of plane angles.
τοιούτων δὲ ἀποτελεσθεισῶν τεττάρων πρῶτον εἶδος στερεόν, ὅλου περιφεροῦς διανεμητικὸν εἰς ἴσα μέρη καὶ ὅμοια, συνίσταται.
And when four such solid angles are completed, the first solid form is constructed, which is capable of dividing the whole sphere into equal and similar parts.
δεύτερον δὲ ἐκ μὲν τῶν αὐτῶν τριγώνων, κατὰ δὲ ἰσόπλευρα τρίγωνα ὀκτὼ συστάντων, μίαν ἀπεργασαμένων στερεὰν γωνίαν ἐκ τεττάρων ἐπιπέδων· καὶ γενομένων ἓξ τοιούτων τὸ δεύτερον αὖ σῶμα οὕτως ἔσχεν τέλος.
The second is formed from the same triangles, but from eight equilateral triangles coming together, having made each single solid angle out of four plane angles; and when six such solid angles are formed, the second body in turn is thus completed.
τὸ δὲ τρίτον ἐκ δὶς ἑξήκοντα τῶν στοιχείων συμπαγέντων, στερεῶν δὲ γωνιῶν δώδεκα, ὑπὸ πέντε ἐπιπέδων τριγώνων ἰσοπλεύρων περιεχομένης ἑκάστης, εἴκοσι βάσεις ἔχον ἰσοπλεύρους τριγώνους γέγονεν.
The third is composed of twice sixty of the elements joined together, having twelve solid angles, each contained by five plane equilateral triangles, and it has been generated with twenty equilateral triangular bases.
καὶ τὸ μὲν ἕτερον ἀπήλλακτο τῶν στοιχείων ταῦτα γεννῆσαν, τὸ δὲ ἰσοσκελὲς τρίγωνον ἐγέννα τὴν τοῦ τετάρτου φύσιν, κατὰ τέτταρα συνιστάμενον, εἰς τὸ κέντρον τὰς ὀρθὰς γωνίας συνάγον, ἓν ἰσόπλευρον τετράγωνον ἀπεργασάμενον· ἓξ δὲ τοιαῦτα συμπαγέντα γωνίας ὀκτὼ στερεὰς ἀπετέλεσεν, κατὰ τρεῖς ἐπιπέδους ὀρθὰς συναρμοσθείσης ἑκάστης·
And the one element, having generated these, was dismissed; while the isosceles triangle generated the nature of the fourth, being constructed in groups of four, bringing their right angles together at the center, thus producing a single equilateral tetragon (square); and six such squares joined together completed eight solid angles, each solid angle being harmonized by three plane right angles.
τὸ δὲ σχῆμα τοῦ συστάντος σώματος γέγονεν κυβικόν, ἓξ ἐπιπέδους τετραγώνους ἰσοπλεύρους βάσεις ἔχον.
And the shape of the body thus constructed became cubic, having six plane equilateral quadrangular bases.
ἔτι δὲ οὔσης συστάσεως μιᾶς πέμπτης, ἐπὶ τὸ πᾶν ὁ θεὸς αὐτῇ κατεχρήσατο ἐκεῖνο διαζωγραφῶν.
And since there was still a single fifth construction, god made use of it for the universe, painting it over.
ἃ δή τις εἰ πάντα λογιζόμενος ἐμμελῶς ἀποροῖ πότερον ἀπείρους χρὴ κόσμους εἶναι λέγειν ἢ πέρας ἔχοντας, τὸ μὲν ἀπείρους ἡγήσαιτʼ ἂν ὄντως ἀπείρου τινὸς εἶναι δόγμα ὧν ἔμπειρον χρεὼν εἶναι, πότερον δὲ ἕνα ἢ πέντε αὐτοὺς ἀληθείᾳ πεφυκότας λέγειν ποτὲ προσήκει, μᾶλλον ἂν ταύτῃ στὰς εἰκότως διαπορήσαι.
If anyone, considering all these things properly, should doubt whether one ought to say that the worlds are infinite or limited, he would think that to deem them infinite is indeed the opinion of one who is ignorant of what one ought to be experienced in; but as to whether it is proper to say that they are in truth by nature one or five, he might more reasonably pause and doubt at this point.
τὸ μὲν οὖν δὴ παρʼ ἡμῶν ἕνα αὐτὸν κατὰ τὸν εἰκότα λόγον πεφυκότα μηνύει θεόν, ἄλλος δὲ εἰς ἄλλα πῃ βλέψας ἕτερα δοξάσει.
Our view, indeed, according to the probable account, declares that god made it by nature one; but another, looking elsewhere in some way, will judge otherwise.
καὶ τοῦτον μὲν μεθετέον, τὰ δὲ γεγονότα νῦν τῷ λόγῳ γένη διανείμωμεν εἰς πῦρ καὶ γῆν καὶ ὕδωρ καὶ ἀέρα.
But let this matter be dismissed; and let us now distribute the classes that have been generated in our account into fire, earth, water, and air.
γῇ μὲν δὴ τὸ κυβικὸν εἶδος δῶμεν· ἀκινητοτάτη γὰρ τῶν τεττάρων γενῶν γῆ καὶ τῶν σωμάτων πλαστικωτάτη, μάλιστα δὲ ἀνάγκη γεγονέναι τοιοῦτον τὸ τὰς βάσεις ἀσφαλεστάτας ἔχον·
To earth, indeed, let us assign the cubic form; for earth is the most immobile of the four classes and the most plastic of bodies, and it is of the greatest necessity that the one having the most secure bases is of this character.
βάσις δὲ ἥ τε τῶν κατʼ ἀρχὰς τριγώνων ὑποτεθέντων ἀσφαλεστέρα κατὰ φύσιν ἡ τῶν ἴσων πλευρῶν τῆς τῶν ἀνίσων, τό τε ἐξ ἑκατέρου συντεθὲν ἐπίπεδον ἰσόπλευρον ἰσοπλεύρου τετράγωνον τριγώνου κατά τε μέρη καὶ καθʼ ὅλον στασιμωτέρως ἐξ ἀνάγκης βέβηκεν.
And as for the bases of the triangles hypothesized at the beginning, the one with equal sides is by nature more secure than that with unequal sides; and the plane constructed from each of them, namely the equilateral tetragon (square) as compared to the equilateral triangle, of necessity stands more stably, both in its parts and as a whole.

Notes

  1. 54aτοῖν δὴ δυοῖν τριγώνοιν — The genitive τοῖν δὴ δυοῖν τριγώνοιν functions as a partitive genitive, presenting the whole group of which the following τὸ μὲν ἰσοσκελὲς and τὸ δὲ πρόμηκες are the constituent parts.
  2. 54bτριπλῆν κατὰ δύναμιν ἔχον τῆς ἐλάττονος τὴν μείζω πλευρὰν ἀεί — The phrase κατὰ δύναμιν is used in a mathematical sense to mean 'in square' or 'by power,' indicating that the square of the longer side (τὴν μείζω πλευρὰν) is three times (τριπλῆν) the square of the shorter side (τῆς ἐλάττονος, which functions as a genitive of comparison).
  3. 55dτὸ μὲν ἀπείρους ἡγήσαιτʼ ἂν ὄντως ἀπείρου τινὸς εἶναι δόγμα — ἡγήσαιτʼ ἂν is an optative with ἄν expressing potentiality. The accusative article τὸ nominalizes the infinitive clause with ἀπείρους [κόσμους εἶναι] as its subject, while δόγμα εἶναι serves as the predicate of the indirect discourse. It features a wordplay between ἄπειρος meaning 'infinite' and 'ignorant.'
  4. 55eτό τε ἐξ ἑκατέρου συντεθὲν ἐπίπεδον ἰσόπλευρον ἰσοπλεύρου τετράγωνον τριγώνου — The subject τό... συντεθὲν ἐπίπεδον refers specifically to the plane composed of the isosceles triangles, namely the 'equilateral tetragon' (ἰσόπλευρον τετράγωνον), while ἰσοπλεύρου τριγώνου ('equilateral triangle') functions as a genitive of comparison modifying the comparative adverb στασιμωτέρως.

Cite this passage

Plato, Timaeus §54-55. Humanitext Reader, https://reader.humanitext.ai/en/text/urn:cts:greekLit:tlg0059.tlg031.humanitext-grc2:54-55

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