“What causes Duḥkha?
In the school of Sāṃkhya it arises from within, or from external influences,
or from extraordinary phenomena such as drought, storm, earthquake.
However, the experience of Duḥkha is not the same for everyone.
The same circumstance may not bring Duḥkha in erveryone.
Hence the cause of Duḥkha is association. Association implies “two”,
that which is “associated to” and that which is the “cause of association.”
In Yoga they are known as Draṣṭṛ and Dṛśya;
that which perceives and that which is perceived.
The next three Sūtra describe them.
How these two get associated is a subject matter of great debate.
Suffice it to say that this mystery is the Lord’s will.”
– T Krishnamacharya on Yoga Sūtra Chapter Two verse 17

“What is the nature of the Dṛśya or what can be perceived?
It has three qualities; it reveals, it acts, it has substance.
It has many components, the objects known and the means to know them.
They serve two roles.
When in strong association with the perceiver they produce pleasure or pain –
when this association is absent they let the perceiver visualise its own nature.
Experience of pleasure or pain is by the perceiver.
Freedom from them is also its fundamental situation.
This freedom is no different from Mukti.”
– T Krishnamacharya on Yoga Sūtra Chapter Two verse 18

“Yoga is not about not enjoying the world because we see it as it really is.”
Rather it is seeing the world as it really is and still enjoying it.
– Paul Harvey on Yoga Sūtra Chapter Two verse 18

“The witness cannot be witnessed.”
– Paul Harvey on Yoga Sūtra Chapter Four verse 18