He does not understand that he himself is the Centre of all and thus forms the basis for all.

Devotee:  What are asanas (postures or seats)? Are they necessary?

Ramana Maharishi:  Many asanas with their effects are mentioned in the Yoga sastras. The seats are the tiger-skin, grass, etc.; the postures are the ‘lotus posture’, the ‘easy posture’ and so on.
Why all these - only to know oneself? “I am the body; the body requires a seat; it is the earth,” thinking thus, he seeks seats. But in sleep did he think of the support or the bed: the bed on the cot and the cot on the earth? Did he not exist in sleep too? How was he then? The truth is - Being the Self, the ego rising up, confusing himself with the body, mistaking the world to be real, differentiating the objects, covered by the ignorance of the ‘I’-conceit, he thinks wildly and also looks for seats. He does not understand that he himself is the Centre of all and thus forms the basis for all. If questioned he talks of the effects of seats and footwear in terms of gravitation, magnetism and so on. Without them he imagines that the power of his austerities will dwindle away. Wherefrom do they all derive their power? He looks to the effects, seeks their causes and imagines them to be the power of seats and of footwear. A stone thrown up falls back to the ground. Why? Owing to the gravitation, says he. Well - are all these different from his thoughts?
Think and say if the stone, the earth and gravity are different from his thoughts. They are all in his mind only. He is the Power and the wielder of it. He is the Centre of all and their support. He is also the Seat. The seat is meant to make him sit firm. Where and how can he remain firm except in his own real state? This is the Seat.