But the philosophical basis for this question is usually not understood at all by those critics who presume to answer the question off-hand in a spasm of polemics.  It is interesting, as an evidence of the shallowness of most contemporary dramatic criticism, to read over, in the course of Mr. Shaw’s nimble essay on The Quintessence of Ibsenism, the collection which the author has made of the adverse notices of Ghosts which appeared in the London newspapers on the occasion of the first performance of the play in England.  Unanimously they commit the fallacy of condemning the piece as immoral because of the subject that it deals with.  And, on the other hand, it must be recognised that most of the critical defenses of the same piece, and of other modern works of similar nature, have been based upon the identical fallacy,—­that morality or immorality is a question of subject-matter.  But either to condemn or to defend the morality of any work of art because of its material alone is merely a waste of words.  There is no such thing, per se, as an immoral subject for a play:  in the treatment of the subject, and only in the treatment, lies the basis for ethical judgment of the piece.  Critics who condemn Ghosts because of its subject-matter might as well condemn Othello because the hero kills his wife—­what a suggestion, look you, to carry into our homes! Macbeth is not immoral, though it makes night hideous with murder.  The greatest of all Greek dramas, Oedipus King, is in itself sufficient proof that morality is a thing apart from subject-matter; and Shelley’s The Cenci is another case in point.  The only way in which a play may be immoral is for it to cloud, in the spectator, the consciousness of those invariable laws of life which say to man “Thou shalt not” or “Thou shalt”; and the one thing needful in order that a drama may be moral is that the author shall maintain throughout the piece a sane and truthful insight into the soundness or unsoundness of the relations between his characters.  He must know when they are right and know when they are wrong, and must make clear to the audience the reasons for his judgments.  He cannot be immoral unless he is untrue.  To make us pity his characters when they are vile or love them when they are noxious, to invent excuses for them in situations where they cannot be excused—­in a single word, to lie about his characters—­this is for the dramatist the one unpardonable sin.  Consequently, the only sane course for a critic who wishes to maintain the thesis that Ghosts, or any other modern play, is immoral, is not to hurl mud at it, but to prove by the sound processes of logic that the play tells lies about life; and the only sane way to defend such a piece is not to prate about the “moral lesson” the critic supposes that it teaches, but to prove logically that it tells the truth.