"Sacrifice of Isaac"

Brunelleschi defined the quadrants of the four-lobed panel using compositional elements that create strong vertical and horizontal axes, but within this structure everything is frozen in a moment of tense, dynamically twisting action. In the upper half, the narrative drama is conveyed by Isaac's contorted pose and open mouth as he cries out in terror, and by the intense focus of Abraham as he leans into his terrible task, counterbalanced by the angel rushing in to stop him, their arms interlocked in a zigzag line of energy that continues down through Isaac's body. Even the ram twists its head back in struggle, echoing Isaac and foreshadowing its fate as a substitute for the human sacrifice. In the lower half, humans and animal alike tend to their basic physical needs, heads down, one turning outward, one inward, and one slowly grazing, oblivious to the drama above. 

The artists were given a year to complete their work, and at the end of that time two main contenders emerged from the initial seven, Brunelleschi and another young goldsmith and sculptor, Lorenzo Ghiberti. Ghiberti's panel was far calmer and more graceful, if less unified in its composition, and, perhaps crucially, was also constructed more efficiently to use less bronze. The commission ultimately went to Ghiberti, who then spent the next two decades completing the twenty-eight panels for the doors. Although Brunelleschi did not win the commission, his panel demonstrates his already evident skill at rationally organizing and activating three-dimensional space, as well as his interest in Classical art, since the figures of the two servants are essentially direct quotations of well-known Roman sculptures. After this point Brunelleschi made few further sculpted works (although his adopted son was primarily a sculptor), perhaps in part out of disappointment over his loss in this major competition. The innovative approach evident in his Baptistery panel, however, would go on to inform much of his subsequent architectural work.