Yet Ghiberti’s ingenuity was sufficient not only to make the designs but to overcome the immense technical difficulties incidental to carrying them out in bronze. Truth to tell, the commission should never have been given to a sculptor. In addition to the difficulties connected with his own art, Ghiberti was faced with the necessity of adding architectural and landscape backgrounds to his reliefs. He strove to solve problems of perspective which even the painters of his day had not mastered. Indeed, for the designer of the Baptistery gates, sculptural relief was rather a branch of the graphic arts than a part of the plastic arts, governed by the rules and subject to the limitations of sculpture. Ghiberti’s life’s work landed his art in a blind alley. For further progress it was necessary that sculpture should be once more informed with its own definite spirit. Ghiberti, or rather his patrons, had failed to realize that sculpture as a descriptive medium has its limitations. It cannot hope to rival painting in the multiplicity of subjects which it can depict with success. It must, therefore, confine itself to subjects which it can express clearly and vigorously. DONATELLO AND THE CHURCH OF OR SAN MICHELE What was denied to Ghiberti was given to his assistant Donatello—the foremost sculptor of the transitional period which preceded Michael Angelo. By his example Donatello re-defined the proper limits and the fittest objects of the art of sculpture. His life’s work was one continued reiteration of the Hellenic lesson that sculpture is the concrete expression of man’s joyful interest in the human form. To the end, his figures never possessed the ideal grace with which Ghiberti endowed a hundred forms in the Baptistery panels. But Donatello had the essential quality of a true sculptor within him. He put aside all desire to rival the painter. He willed to express himself by form and form only. This fact alone invests his work with an importance and interest in the history of pure sculpture which the more graceful productions of Ghiberti cannot claim. Donato di Betto Bardi, to give Donatello his correct title, was the son of a wool-comber. He had entered Ghiberti’s studio as an assistant in 1405, at the age of nineteen. His experience with Ghiberti gave him the technical skill to carry out an ambition that dated from boyhood. Before Donatello was thirty, the chances of the age gave him a series of unique opportunities of making his dreams realities.