What does it mean?
Rapture; bliss; delight. In meditation, a pleasurable quality in the mind that reaches full maturity upon the development of the second level of jhāna.
-from Access to Insight
Why does it matter?
Pīti is another word connected to jhana. Recall that the jhanas are deep states of meditative absorption and the culmination of the eightfold path. In the first jhana pīti is there, but it is somewhat obscured by vitakka-vicara (applied and sustained thought/application of mind). It comes to full power in the second jhana.
Some teachers say that the arising of pīti is THE key sign that one has entered jhana. This is the jhana light position that I will explain more in Jhana Wars. For other teachers, pīti can arise outside of jhana, although it is always a sign of good concentration.
Pīti feels like a physical experience, but it arises from mental application.
In Bhikkhu Ñánamoli’s translation of the Visudimagga, the are explained like this: “Its function is to refresh the body and the mind; or its function is to pervade (thrill with rapture). It is manifested as elation. But it is of five kinds as minor happiness, momentary happiness, showering happiness, uplifting happiness, and pervading (rapturous) happiness. Herein, minor happiness is only able to raise the hairs on the body. Momentary happiness is like flashes of lightning at different moments. Showering happiness breaks over the body again and again like waves on the seashore.”
It can also feel like chills down the back, or a feeling of wonderful coolness throughout the body. It is unmistakable! And it is also a very powerful tool. Experiencing pīti can be much more powerful than pleasant physical sensations like eating good food, stepping into a warm shower, or even orgasm. It is easier to relinquish these sensual pleasures when one has access to the power of pīti!
Of course, some people claim it can go a lot further than that. The Visudimagga goes on to say, “Uplifting happiness can be powerful enough to levitate the body and make it spring up into the air. “ Buddhaghosa relates a story where a woman was told that she shouldn’t go hear a dhamma talk since she was pregnant. Her parents told her to wait while they went to the dhamma talk for her. But after they left she became so overcome with pīti at hearing the ceremonies in the distance that he “sprang up into the air” and landed at the dhamma talk before her parents. That’s some pīti!!