The Doctrine of the Mean here takes a form in which it has impressed subsequent thinkers, but which has less importance than is usually ascribed to it. In the “Table of the Virtues and Vices,” each of the virtues is flanked by two opposite vices, which are respectively the excess and defect of that which in due measure constitutes the virtue. Aristotle tries to show that this is the case in regard to every virtue named and recognised as such, but his treatment is often forced and the endeavour is not very successful. Except as a convenient principle of arrangement of the various forms of praiseworthy or blameworthy characters, generally acknowledged as such by Greek opinion, this form of the doctrine is of no great significance. Books III-V are occupied with a survey of the moral virtues and vices. These seem to have been undertaken in order to verify in detail the general account, but this aim is not kept steadily in view. Nor is there any well-considered principle of classification. What we find is a sort of portrait-gallery of the various types of moral excellence which the Greeks of the author’s age admired and strove to encourage. The discussion is full of acute, interesting and sometimes profound observations. Some of the types are those which are and will be admired at all times, but others are connected with peculiar features of Greek life which have now passed away. The most important is that of Justice or the Just Man, to which we may later return. But the discussion is preceded by an attempt to elucidate some difficult and obscure points in the general account of moral virtue and action (Book III, cc i-v). This section is concerned with the notion of Responsibility. The discussion designedly excludes what we may call the metaphysical issues of the problem, which here present themselves, it moves on the level of thought of the practical man, the statesman, and the legislator. Coercion and ignorance of relevant circumstances render acts involuntary and exempt their doer from responsibility, otherwise the act is voluntary and the agent responsible, choice or preference of what is done, and inner consent to the deed, are to be presumed. Neither passion nor ignorance of the right rule can extenuate responsibility. But there is a difference between acts done voluntarily and acts done of _set_ choice or purpose. The latter imply Deliberation. Deliberation involves thinking, thinking out means to ends: in deliberate acts the whole nature of the agent consents to and enters into the act, and in a peculiar sense they are his, they _are_ him in action, and the most significant evidence of what he is. Aristotle is unable wholly to avoid allusion to the metaphysical difficulties and what he does here say upon them is obscure and unsatisfactory. But he insists upon the importance in moral action of the agent’s inner consent, and on the reality of his individual responsibility. For his present purpose the metaphysical difficulties are irrelevant.