Charaka Samhita – Sutrastana – Chapter 1
Mind, soul and body. These three are like a tripod; the world is sustained by their combination. They constitute the substratum for everything. This combination is what we call Purusha. It is sentient and the main subject matter of Ayurveda. It is due to them, that light has been shed on Ayurveda.
The entire worldly life depends on the combination of mind, soul and body. This combination is likened to a tripod. The simile is particularly significant. A tripod can sustain itself, so long as none of its three constituents are disturbed. The tripod in the present context constitutes sentient beings in entirety.
The trio includes the sense organs along with their objects, buddhi (intelligence) and ahamkara (sense of self or ego). The latter two are included under ‘soul’, while the former one under ‘body’. The mind occupies a very important place in this trio, as the entire body’s activities are controlled by it.