I was told:
“Consider a cup. It’s strange that what makes it really useful as a cup is not the cup itself or the material it is made of but the empty space within it. Consider a house. It’s strange that it is the empty space enclosed by the brick or wooden structure that people actually live in.”
This shows that “What is present is necessary; what is not is essential.”
Not just the flesh, but the spirit.
Not just the body, but the soul.
Not only the maths and sciences, but the arts and literature.
Not only without, but within.
Not just what can be seen, but what cannot.
Not just what is spoken, but what is not.
Not just what is present, but what is not.
Reminds you of Taoism doesn't it? lol