In reply to an e-mail, Daaji clarified why, in Heartfulness, we begin with the last three steps of Ashtanga Yoga instead of Yama and Niyama.
The Heartfulness Twist to Ashtanga Yoga
No-thingness does not mean the absence of mind, intellect, ego, consciousness, and physical existence. The ultimate achievement does not deny their presence. The ultimate blossoming only shows us the beauty of all that is, since there is a great shift in the understanding of the body, mind, intellect, ego, and consciousness. They are the vehicles that become finely tuned with the inner being we call the soul.
Meditation is the pathway to ultimate nothingness. Meditation helps us refine the mind, intellect, ego, and ultimately consciousness. A person with refined subtle bodies cannot harm themselves or others by any means. Right and wrong, good and bad are easily discernible by such a mind. With sharpened Viveka (discriminative intelligence), a developed mind becomes the perfect vehicle.
Having begun the eight-fold path of Ashtanga Yoga with Dharana, Dhyana, and Samadhi, we are able to appreciate Yama and Niyama. Whereas if we begin with Yama, it is like putting the cart before the horse.