Every time we meet as a sangha, we close our practice by chanting the Four Bodhisattva Vows. The first of these is, “sentient beings are numberless, I vow to save them”. What exactly are sentient beings? What does Zen mean by sentience?
The English word sentience comes from the Latin sentire, ‘to feel’. But the meaning of sentience is not just feeling pleasure or pain, it is knowing the sensations are being felt. The philosopher, Thomas Nagel, explored this with his phrase, “What is it like to be a bat?”. We can know what a bat looks like, where it lives, what it eats, how it gets what it eats. Science can describe infinite minutiae about bats. But it doesn’t know what feels like to be a bat. We know the molecular formula of chocolate, the atoms which comprise it and how they are ordered. In a laboratory we can even synthesize things that taste almost exactly like chocolate. But none of this is what chocolate tastes like, what it smells like, how it feels in the mouth. The term for this is qualia, the knowingthis ‘what’ of a particular sensation.
Qualia require a knower. Qualia describes the fundamental duality between knower and known. It is one way to define sentience. Not “cogito, ergo sum”, Descartes famously mistranslated phrase, “I think therefore I am.” Qualia is more like ‘I know that I think, therefore I am’. It is one (of many) definitions of consciousness, of “self-awareness”. There numerous rabbit-holes coming from this line of thought. For example: Chuang-tzu’s metaphor, “How do I know I am not merely a character in a butterfly’s dream?” Some other time perhaps.
To be sentient requires an object of sensation and a knower of sensation. A gap between ‘what is out there’ and how it is known ‘in here’. Buddhism takes this a step further in its teaching of the vijnanas, a teaching which describes a triad. An object of sensation, an organ of sensation, and an awareness (oh oh) of how these coalesce. This is not a sequential process, rather a simultaneity. Another rabbit hole.
Provisionally speaking, sentience is self-awareness. But this is a limit of our understanding. It is very anthropomorphic. We really don’t know what it is like to be a bat.
When a paramecium, a single-celled organism, wiggles its flagella to propel it away from a noxious stimuli, does it know it or not? The Western world view says no, it is insentient. But its motion is an expression of self-awareness, fleeing from harm. Science can’t imagine it knows it’s fleeing from harm. When a car runs a red light and you slam on the brakes, do know that you are doing it? Are you sentient or insentient in that split-second moment? Eihei Dogen Zenji repeatedly says, “Buddhas and sentient beings…”, suggesting a division, that Buddha’s are insentient. What is he saying? Is it ‘the lights are on but no-one is home’?
Enjoy your sentient Buddha-hood.