as ‘conformity to measure’ [Greek:  metriotaes], by which he (Plato) proposes to discriminate between good and evil.  The concluding qualification of virtue—­’a rational determination, according to the ideal judicious man’—­is an attempt to assign a standard or authority for what is the proper ‘Mean;’ an authority purely ideal or imaginary; the actual authority being always, rightly or wrongly, the society of the time.

Aristotle admits that his doctrine of Virtue being a mean, cannot have an application quite universal; because there are some acts that in their very name connote badness, which are wrong therefore, not from excess or defect, but in themselves (VI.).  He next proceeds to resolve his general doctrine into particulars; enumerating the different virtues stated, each as a mean, between two extremes—­Courage, Temperance, Liberality, Magnanimity, Magnificence, Meekness, Amiability or Friendliness, Truthfulness, Justice (VII.).  They are described in detail in the two following books.  In chap.  VIII., he qualifies his doctrine of Mean and Extremes, by the remark that one Extreme may be much farther removed from the Mean than the other.  Cowardice and Rashness are the extremes of Courage, but Cowardice is farthest removed from the Mean.

The concluding chapter (IX.) of the Book reflects on the great difficulty of hitting the mean in all things, and of correctly estimating all the requisite circumstances, in each particular case.  He gives as practical rules:—­To avoid at all events the worst extreme; to keep farthest from our natural bent; to guard against the snare of pleasure.  Slight mistakes on either side are little blamed, but grave and conspicuous cases incur severe censure.  Yet how far the censure ought to go, is difficult to lay down beforehand in general terms.  There is the same difficulty in regard to all particular cases, and all the facts of sense:  which must be left, after all, to the judgment of Sensible Perception [Greek:  aisthaesis].

Book Third takes up the consideration of the Virtues in detail, but prefaces them with a dissertation, occupying five chapters, on the Voluntary and Involuntary.  Since praise and blame are bestowed only on voluntary actions,—­the involuntary being pardoned, and even pitied,—­it is requisite to define Voluntary and Involuntary.  What is done under physical compulsion, or through ignorance, is clearly involuntary.  What is done under the fear of greater evils is partly voluntary, and partly involuntary.  Such actions are voluntary in the sense of being a man’s own actions; involuntary in that they are not chosen on their own account; being praised or blamed according to the circumstances.  There are cases where it is difficult to say which of two conflicting pressures ought to preponderate, and compulsion is an excuse often misapplied:  but compulsion, in its strict sense, is not strength of motive at all; it is taking the action entirely out of our own hands.  As regards Ignorance, a difference is made.