Let us ask the question: Suppose I had explained to someone the word “red” (or the meaning of the word “red”) by having pointed to various red objects and given the ostensive explanation. ‒ ‒ What does it mean to say, “Now if he has understood the meaning, he will bring me a red object if I ask him to”? This seems to say: If he has really got hold of what is in common between || to all the objects I have shewn him, he will be in the position to follow my order. But what is it that is in common to these objects?