but its easy to spin it around. The wall isn't light, but the individual bricks are light.

Weight is a property of brick, and more weight is a property of more brick.

Well if you consider every particles to have weight as property, photons dont.
If you are using the term weight strictly, in space we can be weightless.

There is something called nuclear mass defect, where the whole is not equal to parts, the total mass of the parts is greater than mass of the whole after fission.
But that is because the binding energy is converted to mass, if l am not wrong.

Isn't that going in the other direction, wholes having qualities parts do not? — Coben

You could just frame it as "lightness" instead, or having the property of "weighing 3-4 kg" or whatever the case may be.

(Just noticed that PossibleAaran pointed out the same thing above.)

Heavy or light makes no difference.

Quantity is not a property of things, but things are a property of quantity. If there is no thing to quantify then there is no quantity. "Nothing" is no thing, so no quantity.

It doesn't matter if it's lightness or heaviness or weight or mass or whatever because each is a property which both brick and wall possess to a greater or lesser degree.

In the original post we used our magic scissors to part a semicircle from a whole circle, and later we used our magic sledgehammer to part a brick from a whole wall.

What is the whole, and what is the weight of this whole, from which we parted our weightless photon?

Heavy or light makes no difference.

Quantity is not a property of things, — Trinity Stooge

Huh? It's definitely a property of a brick that it weighs 3kg on Earth, say (because of its mass).

Huh? It's definitely a property of Earth that it weighs 3kg on a brick, say (because of its mass). And it's definitely a property of the Moon that it weighs 0.5kg on a brick, say (because of it's mass). The property of the brick is mass, the property of the Earth is mass, and the property of the Moon is mass. Weight is a property of our apparatus.

To clarify:
What we quantify is neither brick nor wall nor Earth nor Moon. What we quantify is apparatus.

"X weighs W" is a way of saying something about X's mass. You're trying to claim that it's not a property of X.