In becoming an enlightened being

In becoming an enlightened being,
this does not destroy the living being,
or take it away, or lose it;
nevertheless, it does mean having shed it.

---Dogen, "Rational Zen"

One has to shed the living being in order to become an enlightened being.

This is similar to an ugly caterpillar that turns into a beautiful butterfly.

The metaphor of the butterfly is close to the original Buddhist meaning of enlightenment, since even the enlightened being is a temporary form of existence.

What truly exists then?

Reality as we think it is supposed to be exists for most people. Yet the true reality of existence is that existence is empty of permanence.

By viewing the world through the lens of impermanence, it is possible to "not destroy the living being, take it away, or lose it" i.e. the Middle Way.