Sun, Enlightenment, Empowerment

The solar metaphors of Plato, Plotinus, imply that it is as enabling visibility that the Sun is most important to humans.  Those Ancients must be aware of it as also a source of warmth, but they apparently find nothing philosophically significant about that function.  But, it is less likely that they are aware of the Modern discovery of the contribution of solar energy, via photosynthesis, to human nutrition, e. g. carbohydrates.  On that basis, perhaps more philosophically significant than as a source of Enlightenment, is a metaphorical Sun as a source of Empowerment, which even Nietzsche misses with his Sun-deity Apollo.