Philosophy, in its true sense, is premised on the idea that the most valuable sacrifice you are capable of making is of yourself.

This is essentially the meaning of Socrates’ statement in the Phaedo that philosophy is preparation for death. Socrates is not advocating suicide (he explicitly rejects suicide as impious) nor is he suggesting that life is bad. But you must sacrifice the lower elements of yourself: your addiction to pleasure and comfort, your fears and anxieties.

To make yourself sacred means to become like the Gods, and that can only be accomplished by sacrificing the ungodly in yourself.

The world is throughout filled with deity; and on this account is according to the whole of itself the image of the intelligible Gods.

Proclus, Theology of Plato, Book VII Chapter 1

[You] should demand your own way in your prayers only if your wishes are supported by your rational judgment - and this, a rational outlook, should be the object of the prayers and efforts of us all, states and individuals alike.

Plato, Laws 687e

By what collected intuition can we perceive a nature exalted above intellect itself? We answer, that this can only be accomplished by something resident in our souls as much as possible similar to the first; for we possess in our inmost recesses something of this exalted nature; or rather, there is not anything endued with a power of participating this first god in which he does not abide.

Plotinus, Enneads III:viii:9

1. The universe is in a constant state of becoming.
2. Everything that is in a process of becoming must have a cause for its becoming.
3. It is impossible for one and the same thing to cause itself to become.
4. Therefore, something beyond the universe causes it to become.

Compare with Timaeus 28a - 29b.

Among desires, some are natural
and necessary, some are natural
and unnecessary, and some are
unnatural and unnecessary
(arising instead from groundless
opinion).

Among natural desires, those that
do not bring pain when
unfulfilled and that require
intense exertion arise
from groundless opinion; and such
desires fail to be stamped out not
by nature but because of the
groundless opinions of
humankind.

Epicurus, Principal Doctrines 29 - 30

I have often spoken here of the Stoic and Pythagorean technique of nightly self-examination. It is a very powerful meditation practice. However, many people will sometimes honestly struggle to think of things they did wrong or need to improve. “I’m usually a good person.” That is probably true, but use the following as one of your metrics, as it is objective.

Sometimes it will be obvious that you did something wrong, but when it isn’t, remind yourself of every time during the day that you worried about, or got angry about, or got sad about something you cannot control. Unless you are enlightened, there will usually be at least one or two things, even if they were relatively minor. Maybe it’s politics, maybe it’s your reputation, maybe it’s a family member or significant other, maybe it’s work, maybe it’s finances - whatever it is, acknowledge that you are trying to control something that you cannot control. You can only control your own thoughts, motivations, desires, and aversions.

As Epictetus says, “Practice, then, from the very beginning to say to every disagreeable impression, ‘You’re an impression and not at all what you appear to be.’ Then examine it and test it by these rules that you possess, and first and foremost by this one, whether the impression relates to those things that are within our power, or those that aren’t within our power; and if it relates to anything that isn’t within our power, be ready to reply, ‘That’s nothing to me.’”

[The soul] must be immortal, both because it knows the Gods (and nothing mortal knows what is immortal), it looks down upon human affairs as though it stood outside them, and like an unbodied thing, it is affected in the opposite way to the body. For while the body is young and fine, the soul blunders, but as the body grows old it attains its highest power. Again,
every good soul uses mind; but no body can produce mind: for how should that which is without mind produce mind? Again, while the soul uses the body as an instrument, it is not in it; just as the engineer is not in his engines (although many engines move without being touched by any one). And if the soul is often made to err by the body, that is not surprising. For the arts cannot perform their work when their instruments are spoilt.

Sallust, On the Gods and the World VIII

If you understand that the only real harm to yourself is harm to your soul, you understand that the only person who can harm you, is you. When others behave wrongly, it’s because their souls are disordered and confused. They are not harming you and cannot harm you. They are harming themselves.

For the ‘the fount of everflowing nature’, that tetractys, is not only the eternal cause of being for all things, but also of their well-being, spreading its own good throughout the whole cosmos like a pure and intellectual light. The soul that holds fast to this cause and that like an eye that wipes itself clean to see clearly is roused to prayer by its concern for the beautiful, and then again, as a consequence of fulfilling its vows, it intensifies its zeal, joining deeds to words and confirming important deeds through dialogues with the divine. By making its own discoveries on the one hand, and by being enlightened on the other, it strives for what it seeks in prayer, and seeks in prayer what it strives for. Such is the union of prayer and zeal.

Hierocles of Alexandria

"Again, therefore, attend to the assertions of our fathers on this subject. For they say, that the Demiurgus is the common father and king of all things, and that to other nations he has distributed Gods, who are the prefects of nations, and the curators of cities, each of which governs his own allotment, in an appropriate manner. For since in the father all things are perfect, and all things are one, but in the natures distributed from him, a different power has dominion in a different divinity, hence Mars presides over the warlike concerns of nations; Minerva over the same concerns in conjunction with wisdom; but Hermes over such as rather pertain to sagacity than bold undertakings; and thus the nations which are governed by the several divinities follow the essence of their presiding Gods."

Emperor Julian, Against the Christians

It is worth noting that the notorious Problem of Evil - why would a perfect and all powerful God create an imperfect world full of pain and evil? - is a far less thorny problem for Platonists than it is for those of Abrahamic faiths.

The reason why lies in the fact that, on the Platonist view, creation of the universe is an essential consequence of God rather than a conscious act of benevolence. Therefore to ask why makes no sense. Rather, the question for the Platonist becomes How? How did imperfection come from perfection?

The entire Platonic system is, from one perspective, an answer to that question, but simply put, it is because that which is created from the essence of something else is necessarily lesser than that which creates it, just as the light of the sun is lesser than the Sun itself.

Minerva, 1598,
Nicolaas Braeu After Karel van Mander the Elder

Just open your eyes and see, for this alone is the eye that sees the great beauty.

Plotinus, Ennead 1.6.9

If you are not yet able to transcend the momentum of pleasure seeking, a first step is to replace problematic pleasures or desires with less problematic ones. You will still be working within the framework of Pleasure = Good, which is incorrect. Therefore, this should not be a long term practice - it's a kind of spiritual Band-Aid. But it might sometimes be the best we can do, and it is better than doing nothing. In the meantime, you should continue to work towards transcending the Pleasure = Good framework, which will always hold you back spiritually.

A common misunderstanding of Platonism is that it is antagonistic to the body or the world. This is not true. Here is a simple way to understand how this is not true:

1. We are to imitate the Gods. Imitation of the Gods is essentially what it means to be virtuous.
2. The Gods are beyond petty pleasure seeking and petty ego complexes.
3. At the same time, the Gods are at all times providentially maintaining and caring for the entire universe.

How could we imitate the Gods if we do not also ultimately have this same care and love for the world (our bodies are a part of the world)?

In God there is no sort of wrong whatsoever; he is supremely just, and the thing most like him is the man who has become as just as it lies in human nature to be. And it is here that we see whether a man is truly able, or truly a weakling and a nonentity; for it is the realization of this that is genuine wisdom and goodness, while the failure to realize it is manifest folly and wickedness.

Plato, Theaetetus 176c

Philosophy is the purification and perfection of human life. It is the purification, indeed, from material irrationality, and the mortal body; but the perfection, in consequence of being the resumption of our proper felicity, and a reascent to the divine likeness. To effect these two is the province of Virtue and Truth; the former exterminating the immoderation of the passions; and the latter introducing the divine form to those who are naturally adapted to its reception.

Hierocles, Commentary on the Golden Verses

How to overcome bad habits and characteristics

1. Sincerely wish that you will be happy, fulfill your highest purpose, and live in tranquility. Sincerely wish to be beautiful before God. Commit to obtain the purity that lies within you and that comes from divinity.

2. Imitate great men, such as Socrates, or any others you know. Remember how they behaved in difficult situations.

3. When anything happens - a temptation or a problematic situation or anything else - call on the aid and support of God. (By the way, it is perfectly correct to use singular God within the context of polytheism. Of course you can call upon a specific God too.)

4. Tell your thoughts and feelings to wait a moment, so that you can see what they’re all about. Tell them you don’t want to be swept away by their speed and momentum. When they ask you to start imagining all sorts of things that might happen, say no and instead think of something beautiful and noble.

5. Offer a sacrifice and prayer. To whatever extent you committed a wrong, gave into temptation, etc., acknowledge that in your sacrifice and prayer.

6. Consciously note every day that goes by since you were last defeated by your problem. “The last time I lost my temper was yesterday.” “The last time I was overcome by lust was three days ago.” Enjoy your victory each time.

7. If you defeat your problem for thirty days in a row, offer a sacrifice to God.

Source: Epictetus, Discourses 2.18