Why do we lay the foundation of Yama, Niyama, Asana, Pranayama and Pratyahara to start with meditation yoga?

 Yama is the observance of silence for a clarified consciousness of the
purpose within mind.
 Niyama is the theory of moral responsibility for the lack of purpose within
mind.
 Asana is the posture for partial fulfillment of the moral responsibility with an
idea of what the purpose might be.
 Pranayama is breathing the feminine element to become the ideal, capable
of conceiving the purpose of life created by Mother Nature.
 Pratyahara is withdrawal of the masculine element for the subjugation of
ego that makes one behave like an ideal with potential, so that one may
meditate on the potential for oneness which make sone the Almighty
Creator of one’s purpose of life and shape the mood, destiny, divinity, and
eternity by fulfilling the desirable purpose.