Platonism is simply the theology derived from the works of Plato. Plato had a scattering of works dealing with a varied number of subjects. Some of his works spoke as if the Greek gods were real, but this seems to be tongue in cheek. In The Republic, Plato lambasts anyone who believes in the Greek gods and posits a monotheistic explanation. Plato’s really influential works describe an ultimate creator. The basic idea for this creator was that he was ultimately “good” and from that attribute all other attributes flowed.

Here is Plato in the Republic, book 2:

Shall I ask you whether God is a magician, and of a nature to appear insidiously now in one shape, and now in another–sometimes himself changing and passing into many forms… or is he one and the same immutably fixed in his own proper image?

…if we suppose a change in anything, that change must be effected either by the thing itself, or by some other thing… And things which are at their best are also least liable to be altered or discomposed; for example, when healthiest and strongest, the human frame is least liable to be affected by meats and drinks, and the plant which is in the fullest vigour also suffers least from winds or the heat of the sun or any similar causes… and will not the bravest and wisest soul be least confused or deranged by any external influence?

…Then everything which is good, whether made by art or nature, or both, is least liable to suffer change from without… surely God and the things of God are in every way perfect… Then he can hardly be compelled by external influence to take many shapes?

…If he change at all he can only change for the worse, for we cannot suppose him to be deficient either in virtue or beauty… Then it is impossible that God should ever be willing to change; being, as is supposed, the fairest and best that is conceivable, every God remains absolutely and for ever in his own form.

… Then it is impossible that God should ever be willing to change; being, as is supposed, the fairest and best that is conceivable, every god remains absolutely and for ever in his own form.

In this text, Plato starts with the assumption that god is only good and not evil. Futhermore, god is perfection in all characteristics (“the fairest and best that is conceivable”). This is Plato’s starting assumption, god is the ultimate good (“the Summum Bonum”) and god is perfect (the best thing conceivable). From these attribute, Plato reasons that god must be immutable.

Here is the logic, often repeated by modern Calvinists: If something perfect were to change, then it would have to change for the worse. If it changes for the worse then it would not be perfect. Thus god does not change.

Plato uses this idea of the perfect being, and in Timaeus, expands on it:

…Now the nature of the ideal being was everlasting, but to bestow this attribute in its fulness [sic] upon a creature was impossible. Wherefore he resolved to have a moving image of eternity, and when he set in order the heaven, he made this image eternal but moving according to number, while eternity itself rests in unity; and this image we call time. For there were no days and nights and months and years before the heaven was created, but when he constructed the heaven he created them also. They are all parts of time, and the past and future are created species of time, which we unconsciously but wrongly transfer to the eternal essence; for we say that he “was,” he “is,” he “will be,” but the truth is that “is” alone is properly attributed to him, and that “was” and “will be” only to be spoken of becoming in time, for they are motions, but that which is immovably the same cannot become older or younger by time, nor ever did or has become, or hereafter will be, older or younger, nor is subject at all to any of those states which affect moving and sensible things and of which generation is the cause. These are the forms of time, which imitates eternity and revolves according to a law of number. Moreover, when we say that what has become is become and what becomes is becoming, and that what will become is about to become and that the non-existent is non-existent-all these are inaccurate modes of expression. But perhaps this whole subject will be more suitably discussed on some other occasion.

Because god is perfect, god cannot be in time. Instead, god must be in an eternal now, not subject to change, while the rest of creation is a moving picture of eternity (like a movie playing out).

So to Plato, god was the Summum Bonum, perfect and timeless. In Plato’s mind, the goal of his religion was to return to a similar state as his god. In this sense, every good practitioner of true religion strives to purify their souls in order to return to a state of immortality.

From Phaedrus:

I will endeavour to explain to you in what way the mortal differs from the immortal creature. The soul in her totality has the care of inanimate being everywhere, and traverses the whole heaven in divers forms appearing–when perfect and fully winged she soars upward, and orders the whole world; whereas the imperfect soul, losing her wings and drooping in her flight at last settles on the solid ground-there, finding a home, she receives an earthly frame which appears to be self-moved, but is really moved by her power; and this composition of soul and body is called a living and mortal creature. For immortal no such union can be reasonably believed to be; although fancy, not having seen nor surely known the nature of God, may imagine an immortal creature having both a body and also a soul which are united throughout all time…

Such is the life of the gods; but of other souls, that which follows God best and is likest to him lifts the head of the charioteer into the outer world, and is carried round in the revolution, troubled indeed by the steeds, and with difficulty beholding true being; while another only rises and falls, and sees, and again fails to see by reason of the unruliness of the steeds. The rest of the souls are also longing after the upper world and they all follow, but not being strong enough they are carried round below the surface, plunging, treading on one another, each striving to be first; and there is confusion and perspiration and the extremity of effort; and many of them are lamed or have their wings broken through the ill-driving of the charioteers; and all of them after a fruitless toil, not having attained to the mysteries of true being, go away, and feed upon opinion.

To Plato, the material world was bondage for the soul. Plato believed that imperfect souls became part of the material world, where perfect souls became part of the immortal world. The souls could change their states by purification. Mortal humans, to become immortal, would have to become like god. Plato explains the working of this purification in Phaedo:

And I conceive that the founders of the mysteries had a real meaning and were not mere triflers when they intimated in a figure long ago that he who passes unsanctified and uninitiated into the world below will live in a slough, but that he who arrives there after initiation and purification will dwell with the gods. For “many,” as they say in the mysteries, “are the thyrsus bearers, but few are the mystics,”-meaning, as I interpret the words, the true philosophers.

But he who is a philosopher or lover of learning, and is entirely pure at departing, is alone permitted to reach the gods. And this is the reason… why the true votaries of philosophy abstain from all fleshly lusts, and endure and refuse to give themselves up to them-not because they fear poverty or the ruin of their families, like the lovers of money, and the world in general; nor like the lovers of power and honor, because they dread the dishonor or disgrace of evil deeds.

Platonic purification was disdain for earthly pleasures. An initiate would disdain all lust, pleasure, money and all other worldly things. The initiate would then meditate on becoming like god. This is the Platonic ascent.

The Platonic religion was one in which god was the ultimate good (“the summum bonum”), god was changeless and timeless perfection, and the goal of human beings were to become purified to join god in immortality. This is actually the meaning of Plato’s famous allegory of the cave.

During and after the time of Jesus, Neo-Platonistism would arise expanding on the attributes of the “summum bonum” and shaping the early Christian church’s views on God. Next article: an overview of neo-platonism.