Moreover, look and see in regard to the thing in question, what is such that if it is the case the thing in question is the case, or what is necessarily the case if the thing in question is the case: if you wish to establish a view inquire what there is such that if it is the case the thing in question will be the case (for if the former be proved to hold, then the thing in question will also have been proved to hold); while if you want to overthrow a view, ask what it is that is the case if the thing in question is the case (for if we show that what follows from the thing in question is not the case, we shall have demolished the thing in question).