Just as how all the living beings on earth begin to do their daily routine in the presence of the rising sun, in the very presence of the expanded consciousness, the body, mind and intellect are energised and go about their work of movement, functions of the sense organs of action and perception, entertaining many choices and deciding all the time.
Bhagavan Sri Sankaracharya gives a very scientific description of the different aspects of our physical, emotional and intellectual being in the poetic verses of the Atma Bodha. Where do all these parts—the body, the senses, the different qualities of a personality born out of stable wisdom, dynamic action and restful inertia and the many actions of the body and mind—operate from? They have their basis and are sustained by the pure consciousness which is the existing, dynamically conscious self.
However, the individual who is identified with the body, mind and intellect, called the Jeeva, entertains a wrong superimposition due to ignorance of the real nature of the self. In such superimposition, he, as all of us do, begins to firmly believe that he is the body, he is all the sense organs; the different qualities and all actions belong to him. This is the very reason why we say many things which are in fact not the reality: “I am tall and thin,” “I am short and fat,” “My weight has trimmed down by 20 kgs.” We also say, “I see very clearly,” “I am unable to hear what you say.”
“I taste this sweet and it is yummy.” “I am feeling the compassion in your argument.” “I am smelling the fragrance of jasmine.” For all these activities, the I is just the witness. Yet we use the wrong language to convey a different meaning. We also say, “I talk, walk and hold things with my hands.” The reality is: the legs are walking, the mouth is talking and the things are being held by the hands.
This word is called Adhyasa or superimposition. When it is done without any thought, in ignorance of the reality and in haste, it is called Adhyasa. However, the same thing, when done purposefully, is called Upasana. For instance, soon Vinayaka Chaturthi celebrations will come. We will either make a Ganesha out of clay or turmeric powder mixed with water. The truth is the base substance, which is clay or turmeric. But we refer to it as Vinayaka. This is Adhyasa or superimposition of an idea over another object.
The example that Sri Adi Sankaracharya gives for this Adhyasa is ascribing blue colour and a dome-shaped roundness for the sky. How much ever high you may go by an airplane, the blue limit of the sky is always receding behind, keeping us ever in hot chase. The possibility of touching the imagined limit of the sky will never ever happen, because it is not there.