Sutra 1.2: Yogaś città vrtti nirodhah ~
"The restraint of the modifications of the mind-stuff is Yoga."
With this sutra, Patanjali wastes no time (or words) in explaining the primary goal of yoga: learning how to quiet the mental chatter. Here, he offers both the definition of yoga and also the practice. Sri Swami Satchidananda says that for a keen student, this single sutra is enough, as the rest only serve to further explain this one. And, "the entire science of Yoga is based on this (sutra)."
The sanskrit word citta refers to the mind field, or the sum total of the mind. Sri Swami Satchidanada explains the different levels within the citta: the ahamkāra, which is the basic mind, or the ego; the buddhi, which is the intellect or discriminative faculty; and the manas, the part of the mind which desires and becomes attracted to things through the senses. In his book, he then offers an adorable yet eloquent and effective cheese analogy to explain the simultaneous interactions within these different parts of the mind, which, in their delicate interplay, constitute the vrtti: the "modifications of the mind-stuff".
All in an instant: the manas pipes up with it's sensory desires - the buddhi adds layers, creating a story - the ahamkara chimes in, pursuing the ego's whims. And the degree to which we both crave and pursue these desires is all dependent on our conditioning, our perspective, and our current values (which do sometimes change). These mental modifications are the chatter in the mind field, and the goal of yoga (according to Patanjali in his Sutra 1.2) is to learn restraint of the citta vrttis - in essence: to still the mind.
This particular lesson, as simple as it sounds yet difficult to achieve, has come back to me a lot recently. I've started to notice that the times in my life when I was most driven by my ego and desires have also been the times I've struggled the most; the more I'm able to let go and quiet my mind, the more content and at peace I am in any situation. I also think this is the main aspect of asana that resonates with me and helps me feel connected to the entire eight-limbed practice of yoga. Asana asks us to find stillness in the body, which (with awareness and practice) can lead us closer to stillness of the mind.
Sutra 1.3: Tadā drastuh svarūpe 'vasthānam ~
"Then the Seer (Self) abides in Its own nature."
When we become unbound by our thoughts, we reach a deep understanding that there is nothing in the world that can truly bind us, and in this acceptance of everything just as it is, we achieve a spiritual liberation that dissolves the illusion of separateness.
As we deepen the awareness that the Seer is not the same as body or mind, we begin to free ourselves of the delusions around our true nature. Sri Swami Satchidananda uses this analogy:
"If the mind has a lot of waves like the surface of a lake, you will be seeing a distorted reflection. To see the true reflection, see that the water is clean and calm and without any ripples. When the mind ceases to create thought forms or when the citta is completely free from vrttis, it becomes as clear as a still lake and you see your true self."