One hesitates when one sees the title: the world is immersed in ideas. We flood ourselves with ideas, and more so our subsequent generations. Therefore, the task of sifting through this deluge to single out a handful of great ideas is daunting. But still, it is a challenge of great meaning, meaning for me, in any case.
Let us start with one of the ancients.
By this time of the century, anyone with a decent education will be jaded by the very names of Socrates and Plato but let us, at least, pay the minimum respect owed him.
His name defines the boundary between the But his greatest contributions were all filtered through his student, Plato, leaving us undecided about the actual originator. The Cave, the Line, the Republic: Plato or Socrates? The ideas Plato repeatedly attributed to Socrates, but technically speaking it's Plato's, because he refined, edited and wrote it down. So, it is perhaps safe for us to say that the credit should reach out to both.
One thing to take away from them is the idea of Ideal Forms. The analogy of the Cave is perhaps the clearest expression of the idea: Imagine a group of people chained up, seated unmoving in a cave with their backs facing the sun. What they perceive are mostly shadows of the outside world cast upon the walls of the cave and they believe that what they perceive is all that the world beyond themselves is.
Then one of them is set free. He (this usually is a he, but I must say that she is equally applicable) is led to the mouth of the cave and his eyes are hurt by the light. But as he becomes accustomed to the light, he begins to see where all the shadows come from. He sees colours and solid shapes, not deformed shadows. He hears actual sounds, not the echoes. And slowly, he begins to turn to the source of light, light that permits him to perceive the world. He sees the sun, with all its majesty.
So what are Ideal Forms? What we see now are shadows. Ideal forms are the actual solid objects. Shadows of an object can surely come in many forms, it changes constantly with the movement of the sun. The object itself does not change, a lot. But look again, what we call a chair comes in many forms but surely we are still able to pinpoint which is a chair and which is not despite the variability. So, there must be a higher entity of a chair casting its shadows in the physical world and since we can all identify chairs it follows that we all know The Chair, the ideal form of a chair. But only in our minds, hence it is detached from the physical world. That, my dear readers, is the Ideal Form.
The analogy of the Line is a more detailed categorization of various levels of perception and thought that I leave for your research pleasure. Also, note that not only chairs and tables have Ideal Forms; such abstract concepts as beauty, justice, truth and freedom have them as well, and being immaterial, these concepts are in fact more real than the physical world as they are closer in nature to the Ideal Forms. Following that, both philosophers believed that the Ideal Forms are innate, that we have knowledge of all the Ideals Forms which are unknown to us because we have forgotten them at birth and therefore easily retrievable with appropriate stimuli.
This then leads us to the other major idea: the Republic. They believed the people needed a philosopher king, a king whose sole responsibility is to lead the people out of darkness and into understanding, especially of the abstract concepts. Socrates claimed to have gone through the painful process of facing the light and seeing the real world, hence concluding it was possible for all but only if a philosopher king was in place to guide and shepherd the people. And so the Republic with its philosopher king.
There is one relatively modern thinker whose ideas stemmed from the same source, but from a different era…
