Black and white boundary unknown, but black and white clear

https://gyazo.com/7a4c90baa25a4fb26f28621139598a3f

Even though black and white may not have clear boundaries, an object may be clearly black.

There is no clear boundary between black and white in the figure.

B claims, "Y is gray, not sure if it's white or black."

Even so, A's claim that "X is black" can be valid.

This is due to a shaky definition of "clear"

B says "black and white is clear" is "for any given x, I know if it's white or black."

A claims, "For a particular X, I know whether it is white or black."

B has stricter conditions.

Do ants and cabbages feel pain? Isn't it impossible to know with today's science? In response to B's assertion that

He argued, "Even if we don't know if an ant or a cabbage feels pain, we can clearly see that a cow does."

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