Changes

Here is the flaw.  Is Set S a member of itself?  If S is a member of itself, then it cannot be a member of itself by the very definition of S.  But if S is not a member of itself, then it must be a member of itself, again by its very definition.  Hence there is a fundamental logical contradiction in this type of set, and in any theory that allows it.

Here is the flaw.  Is Set S a member of itself?  If S is a member of itself, then it cannot be a member of itself by the very definition of S.  But if S is not a member of itself, then it must be a member of itself, again by its very definition.  Hence there is a fundamental logical contradiction in this type of set, and in any theory that allows it.