Schopenhauer had said, "To preach morality is easy,
to give it a foundation is hard."
When I read Yoga Darshan, I found that giving foundation to morality is ridiculously simple. Yog is Chittavrittinirodhah. Everything that enables it is moral. That which hinders it is immoral.

Maharishi Patanjali says, अहिंसासत्यास्तेयब्रह्मचार्यपरिग्रह यमः।
Meaning, non-killing, truthfulness, non-stealing, continence, and non-receiving, are called Yama.
And, शौचसंतोषतपः स्वाध्यायेश्वेरप्रणिधानानि नियमः।
Meaning, internal and external purification, contentment, +

mortification, study, and worship of God, are the Niyamas.

Yama and Niyama are to be practised if one has to reach higher stages of Yoga.
But why does one have to do Yoga in the first place?
Because real nature of self is manifested in Samadhi which is attained through Yoga. +

At other times, वृत्तिसारूप्यम. Meaning, we identify ourselves with Vrittis.
These vrittis are governed by gunas, and can be both क्लिष्ट and अक्लिष्ट.

Maharishi Patanjali writes, मैत्रीकरुणामुदितोपेक्षणां सुखदुःखपुण्यापुण्यविषयाणां भावनातश्चित्तप्रसादनम्।
Meaning, friendship, mercy, gladness, indifference, being
thought of in regard to subjects, happy, unhappy, good and evil respectively, pacify the Chitta.

And on and on.