This may be true, but only to a limited extent. If human experience is limited, then so is the acquired knowledge and truth can not exist partially only. On the one hand. On the other hand, it is safe to say that unlimited experience is impossible at least empirically (419a).
Therefore, truth might be based on experience but experience is not enough. The fact that people are chained to the wall is a metaphor which suggests the fact that human perceptions are influenced and shaped by the environment we live in through its customs, beliefs and values. It becomes obvious how difficult it is to have a free mind. Returning to the issue of experience, we may have a person breaking free from the chain and thus being able to move around the cave.
Now he can see the statues and the fire and with the use of reason he understands that the shadows on the wall were not reality but an illusion. We now understand the importance of science and scientific development, as well as that of the importance of the manner in which the mind works. Had the freed person not been clever enough to make a connection between the statues and the fire, he would have remained ignorant.
Notwithstanding the newly acquired knowledge, we are still inside the cave and knowledge is still limited. Truth is to be found outside the cave, where the individual can see the existence of a multitude of objects thanks to the sunlight (445e).
The sun's light is blinding at first. Man is not ready to understand everything (the mind or the intellect?). Then he gets used to the light and is able to see all the illuminated objects. He understands that the real world is outside the cage and that one needs the sunlight in order to have...
Now that he is "illuminated," he realizes that his task is go back to the cave and teach all the people who are still in chains about the real nature of the truth. At this point we can speak about a strong principle of goodness (484a).
The analogy of the sun is a very important element when discussing Plato's The Republic. On the one hand we have the eye which is a symbol for the human mind (soul?). On the other hand, there are the objects, which exist independently of man's perception. At this point we can speak about forms. Then there is the sun, the agent which allows the human mind to come in contact with the forms. From this point-of-view, the sun is a supreme form, a form of the good (514a).
There are several interesting analogies that can be analyzed here. When saying that the eye can not see the objects in the absence of light one understands that the form of good is imperatively necessary in order for the mind to create a connection with the forms.
The nature of the eye and the one of the sun must be similar in order for them to be able to establish a connection. In other words the mind and the soul are to be of a nature similar to the one of the good (543a).
Since the sun not only allows things to be perceived, but actually to exist, we can only deduce that the god is the root of all existence and not just the factor which allows existing objects to be perceived. The moral dimension of knowledge and the truth is worth underlining at this point (otherwise why would the man outside think that it is his duty to go back into the cave and teach the others about the truth?).
Bibliography:
Plato, The Republic
