Three types of Śiṣya:
1. The student doesn’t get started e.g. doesn’t get beyond Saṃkalpa
2. The student starts, but when there is an obstacle, stops.
3. The student starts, but when there is an obstacle, takes it as a challenge
– T Krishnamacharya’s commentary on Yoga Sūtra Chapter One verse 22

Question to TKV Desikachar on Yama and Niyama:
“The idea behind Yama and Niyama is the attitude we have to the inside and outside.
If I don’t know what is true there is no question of telling the truth.
However there is the intention, because one day it may become a reality.
Even though some of these things are not there in the beginning, if the intention is sincere then one day it will become an action if conditions and our psychological state change.
Yama as telling the truth also means discretion.”
– TKV Desikachar France 1983

“Saṃkalpa is mainly the intention to do something,
to be serious about my goal; it is something I feel I must do.
Saṃkalpa must be on both parts: student and teacher,
like when we chant ‘saha nāvavatu…’.
Saṃskāra means the purification,
like cleaning a vessel before I use it for another purpose.
It’s a kind of Viyoga or separation.
It concerns how I prepare for the situation.
The Saṃskāra is an effort in both directions: student and teacher.
Saṃyoga means there is a good exchange;
something begins to happen, something is given and something is received.
The best teaching has all three of these.”
– TKV Desikachar speaking with his senior Western students London 1998

“Saṃkalpa is a serious intention between and both from teacher and student.
The less the depth of Saṃkalpa, the less the depth of what follows.
Once this is there what is required is Saṃskāra.
Saṃskāra is to remove the obstacles.
In a way it is Viyoga, so that certain things that get in the way are put aside.
Saṃskāra is like cleaning a vessel before you cook.
Saṃyoga is where something begins to happen.
The accumulation of what begins to happen between teacher and student is Saṃyoga.
Proportionate to the quality of the three, the output will be different”
– TKV Desikachar speaking with his senior Western students London 1998