Posture is the physical aspect of holistic tradition that is yoga. In this case, we talk about a position that leads to physical and mental stillness that are the fundamental conditions of Samadhi or realization. Therefore, the conditions mentioned by Patanjali are stability and comfort.
It has been inferred that Patanjali refers in general terms to the seat, since asana also means seat in Sanskrit and that the great masters have searched for a comfortable meditation postures such as the Buddha piled up grass to sit in meditation. Traditionally, the stance of most emblematic yoga postures are the lotus to keep the spine straight and body relaxed if we are used to this practice.
Attention in the body and tries to counter the fluctuations of the mind, the process of thoughts and feelings that constitute mental activity. The stability and comfort are necessary to release any physical effort. As everything is connected, this comes from the mind. The positions are a mirror reflecting our psychological process, identification with the world and our conditionings.
To relax in a posture implies releasing any desire to feel good, conditioned by our preconceptions and perceptions. Asanas ask us to drop, allowing just the way things are. In the same way, to help achieve this physical stillness, there needs to be unity and integration which dissolve the limitations we have to see light and infinite reality because we are all illuminated. Our essence is pure bliss with pure consciousness. All our limitations come from our identification with our mind, body and senses that make us believe divided.
Physical stillness of the asanas are a physical manifestation that begin to reflect the nature of consciousness where duality vanishes and spirit tastes the same to the world. Physical and mental relaxation should generate yoga posture to promote a state of equanimity that allows the duality of the world to be diluted, the pairs of opposites represented by the cold and heat, pleasure and pain, self and others.
This union (samapatti) removes the causes of suffering (desires) duality and they need to create their illusory capacity. The Upanishads are a part of the Vedas, the foundational texts of the philosophical tradition of India and Vedanta where the body of knowledge that supports yoga follows.
This process is long and requires constant return to mental relaxation and integration, through what we might call methods, action or practice (abhyasa) despite mental activity, discomfort, judgments and feelings that may arise. Abhyasa is a bit paradoxically, effort and perseverance to reach the state of complete lack of effort. It is the lack of effort, within that silence, surrender and let flow, which brings us closer to our true nature which is free and happy.
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