To understand the philosophy of Yoga more deeply we need to understand its system. As a system of Yoga defines the structure of Yoga. Yoga is an ancient Indian science which developed by the great Yogis of India. The Adiyogi which is the Shiva was the first who seeded the concept of Yoga. Many ancient Indian scriptures like Patanjali Yogasutra, Shiva-Samhita, Srimad Bhagavad Gita etc are the pioneer scripture explain the philosophy & system of Yoga.
The system of Yoga is built entirely on the philosophy of the Sankhyas. According to the Sankhyas, nature is both the material and efficient cause of this universe. Of this nature, there are three sorts of materials, the Sattva, the Rajas, and the Tamas. The Tamas material is all that is dark, all that is ignorant and heavy; and the Rajas is activity. The Sattvas is calmness, light. When nature is in the state before creation, it is called by them Avyaktam, undefined, or indiscrete; that is, in which there is no distinction of form or name, a state in which these three materials are held in perfect balance. Then the balance is disturbed, these different materials begin to mingle in various fashions, and the result is this universe. In every man, also, these three materials exist. When the Sattva material prevails knowledge comes. When the Rajas material prevails activity comes, and when the Tamas material prevails darkness comes and lassitude, idleness, ignorance.
According to the Sankhya theory, the highest manifestation of this nature, consisting of these three materials, is what they call
Mahat, or intelligence, universal intelligence, and each human mind is a part of that cosmic intelligence. Then out of Mahat comes the mind. In the Sankhya Psychology, there is a sharp distinction between Manas, the mind function, and the function of the Buddhi intellect. The mind function is simply to collect and carry impressions and present them to the Buddhi, the individual Mahat, and the Buddhi determined upon it. So, out of Mahat comes mind, and out of mind comes fine material, and this fine material combines and becomes the gross material outside—the external universe.
The claim of the Sankhya philosophy is that beginning with the intellect, and coming down to a block of stone, all has come out of the same thing, only as finer or grosser states of existence. The Buddhi is the finest state of existence of the materials and then comes Ahamkara, egoism, and next to the mind comes fine material, which they call Tanmatras, which cannot be seen, but which are inferred. These Tanmatras combine and become grosser, and finally produce this universe. The finer is the cause, and the grosser is the effect. It begins with the Buddhi, which is the finest material and goes on becoming grosser and grosser until it becomes this universe.
