Final answer:
Platonic "ideas" are immaterial, unchanging, eternal objects according to Plato's idealism.
Step-by-step explanation:
Platonic "ideas" are a group of immaterial, unchanging, eternal objects in the mind of God. According to Plato's idealism, the physical world is not real but constantly changing, while the world of ideas is a realm of absolute truth. Plato believed that these ideas exist independently of human minds, and whenever we grasp an idea, we are using our mind to conceive something from the ideal world.