Then there were these five hundred monkeys hanging out in some trees next to a large pool of water. After night came down, the chief monkey saw the moon reflected in the water below him. He asked all the others come over to his tree and join hands and tails to form a chain, so that he’d be able to lean out over the pool and grab the moon. Well, that many monkeys in one tree was just too much and the branches broke and all five hundred of the primates fell into the water and drowned.
The point of the story you can plainly see. As long as you are blinded by illusion, all that waits for you is suffering. So don’t go mistaking a reflection for the real moon.
In Genjo-koan (“Realizing the Prime Point’), Dogen wrote, “Awakening is like the moon reflected on water.”
One meaning of this statement is that awakening or Buddhahood is not a destination to be reached in the remote future but a potential already inherent in life. If we see it as something outside of ourselves, it’s an illusion.
Earlier in the essay Dogen says, “Those who greatly awaken to illusion are Buddhas. Those greatly deluded amid awakening are sentient beings. Some people continue to awaken beyond awakening. Some continue amid their illusion deeper into further illusion.”
Another Dogen work, Bussho (“Buddha Nature”), begins with a quote from the Nirvana Sutra: “All sentient beings have buddha nature.” Some paragraphs later, he takes exception to this statement, asserting that it is incorrect to say that sentient beings “have” or “possess” buddha nature because sentient beings are buddha nature, indeed all reality is buddha nature.
Conventionally speaking, it is not wrong to say that all sentient beings have buddha nature because we can access it. If we could not access it then we would not have it. Accessing buddha nature means to develop this potential, nurture it.
Furthermore, we have something, what Buddhism provides, the means to actualize awakening, to make it a common experience, not an extraordinary event.