These are some of the obstacles peculiar to one subject or another, as to which it would be impossible to pass judgment once for all.

It is for genius to overcome, not for treatises or poetry to evade them.
A final argument, taken from the very bowels of the art, would of itself suffice to show the absurdity of the rule of the two unities.
It is the existence of the third unity, unity of plot--the only one that is universally admitted, because it results from a fact: neither the human eye nor the human mind can grasp more than one _ensemble_ at one time.

This one is as essential as the other two are useless.

It is the one which fixes the view-point of the drama; now, by that very fact, it excludes the other two.

There can no more be three unities in the drama than three horizons in a picture.