Let us now examine the scope of “emptiness” (sunyata) by introducing the eighteen types of Openness. This is relevant to seeing how work and study on the “perfection of wisdom” dove-tails with the abodes of the Sublime Abode and the Divine Abode” Emptiness-Openness, Signlessness and Desirelessness.

These types are:

1. Inner Openness (adhyatma-sunyata)
2. Outer Openness (bahirdha-sunyata)
3. Inner and Outer Openness (adhyatma bahirdha-sunyata)
4. Openness of Openness (sunyata-sunyata)
5. Great Openness (maha-sunyata)
6. Openness of ultimate meaning (paramartha-sunyata)
7. Openness of what is compounded (samskrta-sunyata)
8. Openness of what is not compounded (asamskrata-sunyata)
9. Openness of boundless or the unlimited (atyanata-sunyata)
10. Openness of the beginningless and the endless (anavaragra-sunyata)
11. Openness of the undispersed (anavakara-sunyata)
12. Openness of the “Being” itself of all beings (prakrti-sunyata)
13. Openness of all the dharmas (sarva-dharma-sunyata)
14. Openness of the self characteristic (sva-laksana-sunyata)
15. Openness of the non-attained (anupalambha-sunyata)
16. Openness of non-beingness (abhava-sunyata)
17. Openness of self-beingness (svabhava-sunyata)
18. Openness of non-beingness of the self-beingness (abhava-svabhava-sunyata) [Nagarjuna’s Mahaprajnaparamita Sastra; Kumarajiva’s translation: Taisho-shinshu-daizokyo, vol. XXV, ch.31]. (The above in Sanskrit)

The eighteen types of Openness are the Prajnaparamita, (Skrt.) elaboration of the abodes of the Noble Abode. According to the Pali tradition, the Three Abodes are listed in ascending order of spiritual and mystical hierarchy: from the Heavenly Abode (four meditations in the Realm of Pure Form) to the Divine, or Sublime Abode (the Four Brahma Vihara), finally to the Noble Abode, consisting of Openness, Signlessness and Desirelessness. In the Mahayana tradition there is a complete transcendence of all three Abodes, one in all three and all three in one. Now there is only interdependence and interpenetration among them. The Mahayana places doctrinal emphasis on “great compassion” (maha-karuna) which is the begin-all and end-all of the Bodhisattva’s Path of Enlightenment for the sake of all beings.