Let us suppose it was the air of Florence, which, according to Vasari, "generates a desire for glory and honour and gives a natural quickness to the perceptions of men," that made Giotto a perfect Florentine, alert, witty, and ever ready with a caustic repartee to anyone who bandied words with him. But though other influences were at work around him, and new images crowded upon his active brain, he kept undimmed the vision of his mountain valley, of the fields, of the days spent in his native village, and, with the eyes of a shepherd he continued to look on all the incidents of human life; he saw the grandeur, the tragedy, the weaknesses, aye, and the humour too, in everything that surrounded him, setting it all down in his frescoes in his own simple and original way. In a few words Mr Ruskin has touched upon the keynotes of Giotto's character when he says: ... "his mind was one of the most healthy, kind and active that ever informed a human frame. His love of beauty was entirely free from weakness; his love of truth untinged by severity; his industry constant without impatience; his workmanship accurate without formalism; his temper serene and yet playful; his imagination exhaustive without extravagance; and his faith firm without superstition. I do not know, in the annals of art, such another example of happy, practical, unerring, and benevolent power." Such was the man who came to Assisi to take up the work left uncompleted by Cimabue and his contemporaries. Giotto was then almost unknown, not having executed any of those great works upon which his fame now rests, and it is not unlikely that the recommendation by Cimabue of his promising pupil to the friars of San Francesco led to his being called there when barely twenty years of age.[73] Opinions differ as to which were his first works and whether he began in the Lower or in the Upper Church, and as there are absolutely no documents relating to the subject, and Vasari is of no help in the matter of dates or precise details, the only way to come to any conclusion is to group these frescoes according to their style. We do not wish to force any arbitrary opinions on this matter, and have simply placed Giotto's work in the order that it seems to us more likely to have been executed. Those who disagree have only to transpose the chapters as they think fit. The chief thing is to enjoy the frescoes and speculate as little as possible on all the contradictory volumes written about them.