τέσσαρα γὰρ πάντων ῥιζώματα πρῶτον ἄκουε· — Empedocles

"His teachings formed a series of poems some five thousand verses in length. Only a hundred and fifty verses have survived from... On Nature yet, the relics are more substantial than those from any other Greek philosopher. From them we can extract a theory which... tackles all three problems of Greek science. ...(a) What are the stable principles behind the flux? (b) What process is responsible for the changes in the flux? (c) What agencies control this process? To these questions Empedokles replied... (a) The enduring principles in the natural world are the four basic types of matter—solid, liquid, fiery and aeriform. ...they are conserved in all material transformations. (b) Change comes about through the mingling and separation of these... which unite in different proportions to produce... familiar objects... (c) The agents responsible... are the two universal powers acting in opposition, which he called allegorically, Love and Strife. ...[T]his [as an explicit theory] was the first appearance in our scientific tradition of an important intellectual model. ...[A]ll material things are organized mixtures of different elementary substances ...And, as developed by his contemporary Anaxagoras, and later by the atomists, this type of matter-theory has been in circulation ever since."

"οὐδέ τι τοῦ παντὸς κενεὸν πέλει οὐδὲ περισσόν."

"ἀλλ’ ἄγε μύθων κλῦθι· μάθη γάρ τοι φρένας αὔξει· ὡς γὰρ καὶ πρὶν ἔειπα πιφαύσκων πείρατα μύθων, δίπλ’ ἐρέω· τοτὲ μὲν γὰρ ἕν ηὐξήθη μόνον εἶναι ἐκ πλεόνων, τοτὲ δ’ αὖ διέφυ πλέον’ ἐξ ἑνὸς εἶναι, πῦρ καὶ ὕδωρ καὶ γαῖα καὶ ἠέρος ἄπλετον ὕψος, Νεῖκος τ’ οὐλόμενον δίχα τῶν, ἀτάλαντον ἁπάντηι, καὶ Φιλότης ἐν τοῖσιν, ἴση μῆκός τε πλάτος τε· τὴν σὺ νόωι δέρκευ, μηδ’ ὄμμασιν ἧσο τεθηπώς· ἥτις καὶ θνητοῖσι νομίζεται ἔμφυτος ἄρθροις, τῆι τε φίλα φρονέουσι καὶ ἄρθμια ἔργα τελοῦσι, Γηθοσύνην καλέοντες ἐπώνυμον ἠδ’ Ἀφροδίτην."

"He tried to address the problem of change by saying that there is not one fundamental arche but four—earth, water, air, and fire—which generate all the material substances in nature by mixing together in various ways under the influence of forces he called Love and Strife."

"ἄλλο δέ τοι ἐρέω· φύσις οὐδενός ἐστιν ἁπάντων θνητῶν, οὐδέ τις οὐλομένου θανάτοιο τελευτή, ἀλλὰ μόνον μίξις τε διάλλαξίς τε μιγέντων ἐστί, φύσις δ’ἐπὶ τοῖς ὀνομάζεται ἀνθρώποισιν."

"Empedocles... changed... [Greek philosophy] from monism to a kind of pluralism. To avoid the difficulty that one primary substance cannot explain the variety of things and events, he assumed four basic elements, earth, water, air and fire.... mixed... and separated by... Love and Strife. Therefore, these latter two... are responsible for the imperishable change. Empedocles describes the formation of the world... First, ...the infinite Sphere of the One, as in the philosophy of Parmenides. But in the primary substance all the four "roots" are mixed... by Love. Then, when Love is passing out and Strife coming in, the elements are partially separated and partially combined. After that the elements are completely separated and Love is outside the World. Finally, Love is bringing the elements together again and Strife is passing out, so... we return to the original Sphere. This doctrine... represents... a more materialistic view... Here for the first time... a few [fundamentally different] substances... explains the infinite variety of things and events. Pluralism never appeals to those who are wont to think in fundamental principles. But it is a reasonable... compromise, which avoids the difficulty of monism and allows... some order."