Crescas refutes these proofs with his new definition of the different levels of material existence. In his opinion, only the common existence of matter and dimension cause the impermeability of the body. A body (matter and dimension) can go inside a void (only dimension), but not inside another body. In this argument we see Crescas utilize the work of the Jewish apostate Abner. Abner explained the birth of Jesus (and transubstantiation) by the argument that Jesus is body without dimension and c