For me, simply put, if I meander back as far as possible in imagination I find that photosynthesis (or photon bombardment of carbon particles) seems probable initiator of animation, which naturally leads to us. From there it's not difficult to conceive of each of our cells as envelopes of photonic interaction, and we ourselves as coherent energetic forms held in temporary stasis by an as yet not fully comprehended elan vital. That any post-vivo coherence sustains seems unlikely but the possibility can't be wholly dismissed. In any case I am content musing on the notion that the accomplishments of consciousness, compassion and conscience constitute the construction of a "soul". And since awareness, perception and illumination are the tools by which such construction is made manifest, "light" seems a definitive term in context.
(It is interesting to me to note that I composed this aphorism by a pragmatic rather than philosophical route. --- mp)