“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 everyone.
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

T Krishnamacharya Yoga Sūtra Study Quotes Collected and Collated