Plutarch, dualism, and the mind of god
Plutarch was a priest, magistrate, ambassador, and essayist born in Chaeronea in Greece around 46CE (d. 120CE). The Greek states had already been part of the Roman Empire for two centuries by the time of his birth, and it is no surprise that at some point Plutarch became a citizen of Rome, changing his name to Lucius Mestrius Plutarchus.
As emphasized in the above writeups, Plutarch (or Lucy, as I'm sure his friends called him) is best known for his biographies, including the famous Parallel Lives. But Plutarch is also important for his philosophical writings, and is considered a reasonably "big name" in the period/school known as Middle Platonism1.
While visiting Athens Plutarch studied under Ammonius, who had set up some sort of Platonic institution. All the great figures Plutarch had heard of - Socrates, Plato, Aristotle - were dead and gone; an era well passed. The Platonism Plutarch came to terms with was a strange medley of ideas that only roughly conform to what is today associated with Plato. For the Middle Platonists, Plutarch included, Platonism was a puzzle rather than a solution, and the pieces all came from different boxes. Inevitably this study involved eclectic introductions of contemporary ideas, including Platonic, Aristotlean, and Stoic thoughts, and to which Plutarch adds a pinch of Persian Gnosticism.
As for the contents of Plutarch's philosophy: the most notable part of it is (what appears to be) an introduction of a fundamental duality.
Traditional Platonism created metaphysical pyramids whose apex was some Good entity. The Academic Platonists after Plato had tried to explain the relationship between the Soul and Intelligence and Matter and Form, for the purpose of explaining how our world derived from higher elements. Although still interested in forming these sorts of schemas, the motivation during Middle Platonism for doing so had subtly changed. Platonists had been influenced by the Stoics for whom (arguably) the world was defined by ideas (logos) in the mind of god. Although the demands of monotheism were not yet in full force (as they would be for the Neoplatonists later), there was nonetheless a sense that Platonists too needed a high power. This highest principle was important not only for legitimating Platonism, but it also provided a necessary pivot for their practical philosophy and its new central mantra - knowing the mind of god. In this light, most Middle Platonists had some sort of ultimate god, which they fiddled with to derive all their other philosophical goodies like matter and form (eg. Eudorus or Antiochus). This ultimate god was good; corruption comes later in creation.
Sitting in our armchairs there's something intuitive about a god that is synonymous with good - even if it doesn't fit the state of affairs - but that's only because we're so steeped in the dominating monotheistic culture. Thanks to the spread of the Roman Empire, and with it, the importation of foreign ideas, Plutarch heard of a fascinating religion in the far east called Zoroastrianism which preached dualism. Insofar as Plutarch could tell, these Zoroastrians believed that there are two ultimate powers, neither superior or prior to the other; one good and one evil.
So Plutarch followed his Middle Platonism fellows in seeking ultimate principles, but he was too tempted by the Persian's dualism to let it go. Dualism seemed to account for so much, including most importantly, why it is that evil persists. What's more, this dualistic explanation paralleled some of the mystical teachings of the Delphian cult. Plutarch served in the famous temple of Apollo in Delphi. This is the same temple to which the Athenians and Spartans sought advice before the Persians invaded, and which later claimed Socrates to be the wisest of all men. The Delphians taught that while Apollo is deathless, it is in the nature of the world that he undergoes transformations into manifold forms, at which times he is called Dionysus. The temple at Delphi serves the eternal cycle of Apollo-Dionysus.
The world is made of opposites: good/evil, creation/destruction, order/chaos; cups half empty and cups half full. The duality that is fundamental is analogous to Apollo/Dionysus. Apollo is ageless and ordered while Dionysus is forever in flux and frenzied. Existence is manifestation. In the beginning there was god everything. Time emerged and the cycle began: Apollo becoming Dionysus becoming Apollo and on forever. The names don't matter. It is only in the manifestation of Dionysus and Apollo that good and evil appear. Until the separation of those two, good and evil do not yet manifest.
But what does this explanation do? Sure it says that good/evil are just manifestations of more basic forces. Plutarch could even, if he wish, secularise those forces and call them order/chaos. Furthermore, it says that even the dual nature of order/chaos is a manifestation, that their cyclic nature hides their underlying transcendental unity.
Remember that for many Middle Platonists, the forms that make the world exist as ideas in the mind of god. To study the forms of the world is to study the mind of god. And vice versa.
Two millennia after Plutarch Nietzsche proclaimed that god is dead and that man is beyond good and evil. Not quite, Plutarch smiles, rather it is god that is beyond good and evil. It is only on this terrestrial plane that good and evil appear. To understand the duality of good and evil is to understand oneself. To know that the world is a cycle of chaos and order is to understand the world. To see the unity behind the duality in the world and in oneself is to know the mind of god.
1 Eras of Platonic thought can be divided into Academic Platonism, which more or less was located in the original school were Plato himself taught; Middle Platonism which was a revival of sorts and a response to the skepticism that had taken hold of the late Academics; Neoplatonism which was another revival, this time with a strong mystical bent.
References include John Dillon's The Middle Platonists, Wikipedia, and an article entitled Plutarch's Dualism and the Delphic Cult by Radek Chlup.