Through Tricycle Magazine someone asked Gil Fronsdal:
In the Mahayana schools, such as Zen, emptiness, or the realization of emptiness seems to be an important part of the path, less so in the Theravada tradition, am I mistaken? And having trained in both traditions how do you reconcile the two?
Emptiness is as important in the Theravada tradition as it is in the Mahayana. From the earliest times, Theravada Buddhism has viewed emptiness as one of the important doors to liberation. Two key Theravada sutras are devoted to emptiness: the Greater Discourse on Emptiness and the Lesser Discourse on Emptiness.
When I was practicing in Burma, I gave a copy of the Heart Sutra to my Theravada meditation teacher. Ignoring the opening and closing, he was happy with the emptiness teaching in the core of the text. He gave a profound dharma talk on the Heart Sutra, saying that this insight is what Vipassana practice aims at.
Over the centuries, emptiness came to have a range of meanings within Buddhism. The greatest change in meaning was in the Mahayana tradition where some quite diverse teachings on emptiness emerged. Even so, the great Indian philosophers of the Mahayana wrote that the standard understanding of emptiness within the Mahayana and within the earlier Buddhist traditions is the same. It is not emptiness which differentiates these traditions.
Though emptiness is important in the Theravada tradition, it is usually not taught as often as in the Mahayana. This might lead some to assume it is absent in the Theravada. One reason it is not taught as often is that emptiness is seen as a liberating insight rather then a philosophical view one needs to understand intellectually. Theravada’s gradual approach to awakening, includes extensive teachings on the functioning of the mind and the foundational practices that allow for the deep penetrative insight into emptiness. Emptiness is sometimes not taught until the student is ready for it.
Another reason Theravada contains fewer teachings on emptiness is that this is not always labeled “emptiness.” For example, Theravada will teach that all things are insubstantial and without essence without calling this an emptiness teaching, even though it is. The frequency with which the Mahayana talks about emptiness is probably matched by the frequency with which the Theravada teaches impermanence and not-self; in practice, both traditions are often pointing to the same thing in these teachings.
A final reason may be that the goal of Theravada practice is not emptiness. The goal is liberation. Emptiness is a means to liberation. While liberation comes with a deep understanding of emptiness, emptiness is secondary to Awakening.