[dofm]

Organising people by the colour of their skin makes exactly as much ontological sense as organising library books by the colour of their cover.

[simianwords]

Can you see the fallacy you are doing here? The parent tried to suggest this: simply because a thing can be in a spectrum doesn't make it unworthy of being a category. You've twisted that analogy into this nonsensical book example.

[dofm]

It’s not a fallacy, it’s a bitter, dark joke.