Ayn Rand begins with axioms, and logically derives her position from there. (Well, maybe. I suspect that at least to some degree, she already had her position, and derived her axioms from there, then argued for her position from her axioms.) So I attack her position by saying that in her third axiom, she mis-defines consciousness, and the rest of her errors follow from her flawed starting position. That's rational. "It leaves me cold" is not a rational response. (It may be an indication that you feel there's something wrong with the position, even if you can't define it or prove it, and that's fine. But it's not a rational response.)