According to Matthew Arnold (in his essay The Study of Poetry) Chaucer's criticism of life has largeness, freedom, shrewdness and benignity, but it lacks "high seriousness". The term "high seriousness" which Arnold says marks the works of Homer. Dante and Milton and Wordsworth, apparently implies a sustained magnificence of artistic conception and execution accompanied by deep morality and spiritual values.
It must be remembered that Arnold laid a great deal of importance on the "actions, human actions" as the proper subjects of poetry. His contention of "high seriousness" is inevitably bound up with this. His concept of poetry being a "criticism of life" is quite satisfied by Chaucer. Chaucer's poetry is steeped with life, and yet there is basic sanity and order in his vision which Arnold should not have missed.
The fun and comedy in Chaucer's writing often blinds one to his basic greatness. His vision is truly Christian in its broad and forgiving tolerance. His vision of the earth ranges from one of amused delight to one of grave compassion. His fresh goodwill and kindly common sense, his sense of joy and warmth are communicated through his poetry especially in The Canterbury Tales. But behind the fun and tolerance there is a sane moral view. Chaucer's tolerance is not born of moral leniency or from a desire to excuse or mitigate the worldliness of the characters as he saw them. The Monk's travesty of the cloister in the name of gracious living finds no exoneration from Chaucer, nor is Chaucer appreciative of the wickedness of the Summonier and the Pardoner. His tolerance is based on deep conviction of human fraility, and his medium of looking at it is irony, not inventive.
When we read the pen portraits of the pilgrims, we can see how clearly Chaucer has suggested the values they live by and what they look for. In these values—the chivalry of the Knight, the Monk's love for hunting, the Doctor's love of gold, the poor Parson's holy thought and work, the Clerk's love for learning and teaching—lies Chaucer's subtle moral judgement.
When Arnold quotes a line from Chaucer as truly classic, he chooses a line expressive of stoic resignation. "O martir seeded to virginitee" from the Prioress's tale. Indeed, all the lines quoted by Arnold as "touchstones" have the ring of stoic resignation. Thus, Arnold's own view seems biased in favour of the obviously solemn and didactic. In fact, Arnold's concept of poetry does not seem to include the genre of comedy. The term "high seriousness" has been interpreted to mean seriousness in the more obvious sense. The poet's criticism of life is not only to be serious, but also seen to be serious. Arnold seems to demand solemn rhetoric. If we interpret "high seriousness" in this light, we can only say that Chaucer's poetry lacks it, for Chaucer was anything but "solemn". However, if we consider "high seriousness" in a broader light, Chaucer's observation of life, his insight into its passions and weaknesses, its virtues and strength is truly great. If we strictly accept Matthew Arnold's contention, then we will have to deny "high seriousness" to all comic writers, even to Moliere and Cervantes.