In Castelvetro (1570) we find a far more complete theory of the drama than had been attempted by any of his predecessors. His work is by no means a model of what a commentary on Aristotle's _Poetics_ should be. In the next century, Dacier, whose subservience to Aristotle was even greater than that of any of the Italians, accuses Castelvetro of lacking every quality necessary to a good interpreter of Aristotle. "He knew nothing," says Dacier, "of the theatre, or of character, or of the passions; he understood neither the reasons nor the method of Aristotle; and he sought rather to contradict Aristotle than to explain him."[140] The fact is that Castelvetro, despite considerable veneration for Aristotle's authority, often shows remarkable independence of thought; and so far from resting content, in his commentary, with the mere explanation of the details of the _Poetics_, he has attempted to deduce from it a more or less complete theory of poetic art. Accordingly, though diverging from many of the details, and still more from the spirit of the _Poetics_, he has, as it were, built up a dramatic system of his own, founded upon certain modifications and misconceptions of the Aristotelian canons. The fundamental idea of this system is quite modern; and it is especially interesting because it indicates that by this time the drama had become more than a mere academic exercise, and was actually regarded as intended primarily for representation on the stage. Castelvetro examines the physical conditions of stage representation, and on this bases the requirements of dramatic literature. The fact that the drama is intended for the stage, that it is to be acted, is at the bottom of his theory of tragedy, and it was to this notion, as will be seen later, that we are to attribute the origin of the unities of time and place. But Castelvetro's method brings with it its own _reductio ad absurdum_. For after all, stage representation, while essential to the production of dramatic literature, can never circumscribe the poetic power or establish its conditions. The conditions of stage representation change, and must change, with the varying conditions of dramatic literature and the inventive faculty of poets, for truly great art makes, or at least fixes, its own conditions. Besides, it is with what is permanent and universal that the artist--the dramatic artist as well as the rest--is concerned; and it is the poetic, and not the dramaturgic, element that is permanent and universal. "The power of tragedy, we may be sure," says Aristotle, "is felt even apart from representation and actors;"[141] and again: "The plot [of a tragedy] ought to be so constructed that even without the aid of the eye any one who is told the incidents will thrill with horror and pity at the turn of events."[142]