As I discuss in this question, by far the most popular school of Hindu philosophy is the Vedanta school. But there are five other Astika or orthodox schools of Hindu philosophy: Purva Mimamsa, Samkhya, Yoga, Vaisheshika, and Nyaya. My question is about the Yoga school, which believed in Purushas or souls, Prakriti of matter/energy, and Ishwara or God. And it’s defining text is Patanjali’s Yoga Sutras.
Now the Yoga Bhashya Vivarana is a subcommentary by the Advaita philosopher Adi Shankaracharya on Vyasa’s Yoga Bhashya, which is itself a commentary on Patanjali’s Yoga Sutras. In this section of the Yoga Bhashya Vivarana, Adi Shankaracharya defends the fact that Ishwara can perceive the world without the use of sense organs. He says that makes sense, given that even humans can perceive darkness without the use of the eye. But then the Purvapakshi or hypothetical opponent raises the objection that darkness isn’t actually a real thing, just the absence of light. Here is how Adi Shankaracharya responds to that:
Again, if darkness were merely an absence, then it should not appear as a weak darkness in brilliant moonlight at night; it ought to be destroyed by that all-pervading light in whose brightness it stands. With an actual thing in the brightness, it is natural that it should have distinctions of weakness and intensity and so on, but not with an absence, for that can have no such distinctions.... Again, in the medical texts, the shadow (of the patient) is said to be sweet, or to be cold. But there can be no sweetness or coldness of what is not a thing. And they call darkness good or bad for certain eye conditions: but an absence could not be so characterized. Furthermore, a shadow is perceived as from a light. If darkness were a non-existent, how could there be – within the circle of illumination – a shadow caused by the light?
I’m interested in the part in bold. My question is, which Ayurvedic texts describe a person’s shadow as sweet or cold?
It’s interesting to note, by the way, that Adi Shankaracharya is citing Ayurvedic texts as an authority. That’s because Ayurveda is one of the four Upavedas.