Intentionalism (section 4) agrees that there is indeed something in common between the veridical and the non-veridical cases. However, this common factor should not be seen as an object, but rather, as intentional content. And finally, disjunctivism (section 5) undercuts the argument from illusion by rejecting the assumption that there must be something in common between the veridical and non-veridical cases. We will discuss these theories below, but first we shall consider the problems with the very idea of sense data, and with the argument from illusion itself.