It is said that the world is empty, the world is empty, lord. In what respect is it said that the world is empty?" The Buddha replied, "Insofar as it is empty of a self or of anything pertaining to a self: Thus it is said, Ānanda, that the world is empty.

Emptiness is a mode of perception, a way of looking at experience. It adds nothing to and takes nothing away from the raw data of physical and mental events. You look at events in the mind and the senses with no thought of whether there's anything lying behind them. This mode is called emptiness because it's empty of the presuppositions we usually add to experience to make sense of it: the stories and world-views we fashion to explain who we are and the world we live in. Although these stories and views have their uses, the Buddha found that some of the more abstract questions they raise — of our true identity and the reality of the world outside — pull attention away from a direct experience of how events influence one another in the immediate present. Thus they get in the way when we try to understand and solve the problem of suffering.

There are two main sources of Indian Buddhist discussions of emptiness: the Mahayana sutra literature, which is traditionally believed to be the word of the Buddha in Mahayana Buddhism, and the shastra literature, which was composed by Buddhist scholars and philosophers.

We state that conditioned origination is emptiness. It is mere designation depending on something, and it is the middle path. (24.18)

When the mind does not lie low, and is not again tossed about, then that being without movement, and not presenting any appearance, culminates into Brahman. Resting in itself, calm, with Nirvana, indescribable, highest happiness, unborn and one with the unborn knowable, omniscient they say. No creature whatever is born, no origination of it exists or takes place. This is that highest truth where nothing whatever is born.