Why am I so wary of Platonism, as expressed in this post?
I am not actually wary of Platonism specifically. Plato is a very skilled writer. He writes with style. In many of the dialogues, if you read with an attentive mind, then Socrates moves beyond asking questions of, say, Euthyphro, to asking questions of me. What do you, mjjhoskin, think of holiness? What is the basis for holiness? What is the basis for this belief of yours? Foundational questions, all of them. Questions that strike at the root of things.
Plato also has some interesting ideas. There’s the ever-popular Cave in The Republic, for example. Timaeus gives us a cosmology not entirely incompatible with reality. Crito gives us the endlessly-speculated myth of Atlantis.
Plato also teaches transmigration of souls. He teaches that this world is not the real world. We have an idea of justice here, an idea of what a table is, an idea of what eros is, but these ideas are not the real things in themselves but shadows of the truth. The true reality, according to Plato, is in the world of forms, where our souls dwell between transmigrations. Platonism also teaches a dualism between body and spirit, between physical and metaphysical. The spirit and the metaphysical are good, the body and the physical are bad. This stems from the theory of forms.
This last paragraph is there to help show why traditional Christianity, “classic” Christianity, ought to be wary of Platonism. Many Christians of the Patristic era liked Platonism too much and created bits of speculative theology that were not in line with Scripture, tradition, or the reasoned account of salvation.
Souls are immortal, according to Platonism — this means that they have a pre-existence in the spiritual realm before becoming incarnate in our bodies. Such is the case in Origenism as well. In fact, from what I’ve seen of Origen and his anathematised beliefs, a great many of them stem from an outworking of Platonist ideas.
One of the most pernicious and persistent Platonic ideas within Christianity is the dualism between body and spirit, between the physical and metaphysical. I think this is in Origen, but it is definitely in the Gnostics and sometimes in the ascetics (but their pagan model was more frequently Stoicism).
The body is not bad.
This is part of true Christian doctrine. In Genesis we are taught that when God created us, He said that His creation was “Very good.” God Himself took on flesh in the Incarnation. He became a man. At the end of time, we shall all be resurrected in a new heaven and a new earth, and we shall have bodies.
The Platonist idea as it manifests itself in Christianty says that our bodies are “fleshly,” and anything that has to do with the body is to be rejected save those things that keep us alive. Modern Christians who have maintained this dichotomy between flesh and spirit sometimes argue things such as, “Dancing is bad because it is all about your body.” Ascetics, on the other hand, argue that you should ignore your body and discipline it. What really matters, however, is mystical experience and seeking God through contemplation. Neglect the body, therefore. Some Gnostics, on the other hand, would argue that since flesh doesn’t matter, do as you please!
Classic Christianity argues that flesh does matter, so treat your body with respect, live morally, and enjoy yourself. Dance. Eat. Drink. Discipline the body, yes, but do so to discipline your whole self, do so to keep it healthy, not to ruin it.
The most pernicious Platonist idea to persist to today is this idea that we are all going to go to heaven when we die, we shall be disembodied and this will be great and this is what we were made for and this world will be destroyed by fire.
Patristic writers (I forget at the moment where I saw this, but it was one of them) lament death because when we die, our bodies and souls are separated, and this is not what we were created for. We were created to have bodies, to walk on earth, to breathe air. This is what the hope of Resurrection is. We will have bodies, but they will be incorruptible. The souls and bodies of the dead will be re-knit together for Judgement Day, and the saved will spend eternity living with those bodies and enjoying the world.
Thus, while there is much in Platonism to commend it, there is also much to be cautious of. The same is true of Aristotelianism, Stoicism, Hinduism, Islam, or Buddhism. Let us not forget that our first commitment is to Christ who was revealed in the Scriptures and has shown Himself through His people throughout history. All pagan ideas, good or ill, are secondary.