What is the central point or idea of The Little Prince?
The main theme of The Little Prince can be summed up, I think, by the Fox's secret, which is "One sees clearly only with the heart. Anything essential is invisible to the eyes." While at first this statement can seem mysterious, we are given many examples of this principle at work in the story. At the beginning of the story, the narrator talks about his drawings number 1 and number 2 -- the first looks like a hat, but, as the second drawing explains, is actually a snake swallowing an elephant. This suggests that appearances can be deceiving -- how "anything essential is invisible to the eye." In the same way, when the narrator is drawing a sheep for the Prince, it is significant that the only satifactory drawing is the one that doesn't represent a sheep at all -- the drawing of the crate. The Little Prince is free in this case to imagine what the sheep inside the crate is like. In this way, we can see that imagination is a kind of knowledge in and of itself, independent of the literal representation of reality.
The Prince's relationship with the Rose is another case in point. The Rose is a vain, demanding, and occasionally untruthful flower, and the Prince goes to great pains to satisfy her needs (he places her under a glass dome to protect her from the wind, is on guard against caterpillars, and worries a great deal about how introducing a sheep to his planet might affect her). However, the Prince's journey shows that he has misunderstood the flower, or his feelings for her. When he comes to Earth and finds the garden of Roses, he is at first distraught because his flower, which he thought was unique, is in fact just one of many flowers. However, what he learns from taming the fox is that the uniqueness of a flower or a person is not based on its appearance, but on one's emotional relationship to it: "You're not at all like my rose...no one has tamed you, and you haven't tamed anyone..." As the fox tells him, "It's the time you spent on your rose that makes your rose so important." In this way, "seeing with the heart" suggests that what is important in life are not external realities, but inner emotional truths.