One of Plato's most well known dialogues, taken from "The Republic", is the description of a cave, in which a group of people live. They are tied hand and foot with their backs against the entrance, so that they can only see the back wall and shadows cast on it by passers by. The people of this cave, having never seen the outside world, believe that these twisted silhouettes are reality, that the shadow of a man is the man, the shadow of a lion is the lion. In the text he adds many layers to this simile, a flickering fire and a curtain wall between which actors with animal cut outs walk, which also casts shadows into the cave, further distorting the cave dwellers image of reality. Plato goes on to add that the voices and sounds of outside would bounce of the back of the cave, deluding its occupants further into thinking the shadows are talking. This is all used to show how an uneducated person may become convinced that something that is just a shadow of the truth is the truth. The idea came from his conept of "Ideal Forms". An "Ideal Form" is the perfect embodiment of its earthy counterpart. Plato thought that we had been in contact with the "Ideal Forms" in some other existence, but could only remember a vague shadow of how they really are, which is why we have the concept of justice, good, bad, etc., but cannot define them. Plato thought that through a rigorous course of philosophical education we could come close to knowing the "Ideal Form", this is described in the text as one of the cave dwellers being untied and taken forcibly out of the cave and into the sunlight to be shown the real world, first by looking at shadows, then reflections, then the objects and people, and finally the moon, stars, and sun. This is how he saw the education of the leaders of his ideal state - the republic, a slow but steady course, leading finally to knowledge of the "Ideal Forms" - the perfect truth.