The commission given to Filippo becoming known among the craftsmen and the citizens, some thought well of it and others ill, as it has ever been the case with the opinions of the populace, of the thoughtless, and of the envious. The while that the preparations for beginning to build were being made, a faction was formed among craftsmen and citizens, and they appeared before the Consuls and the Wardens, saying that there had been too much haste in the matter, and that such a work as this should not be carried out by the counsel of one man alone; that they might be pardoned for this if they had been suffering from a dearth of excellent masters, whereas they had them in abundance; and that it was not likely to do credit to the city, because, if some accident were to happen, as is wont to come to pass sometimes in buildings, they might be blamed, as persons who had laid too great a charge on one man, without considering the loss and the shame that might result to the public interest; wherefore it would be well to give Filippo a companion, in order to restrain his rashness.
Now Lorenzo Ghiberti had come into great repute, by reason of having formerly given proof of his genius in the doors of S. Giovanni; and that he was beloved by certain men who were very powerful in the Government was proved clearly enough, since, seeing the glory of Filippo waxing so great, they wrought on the Consuls and the Wardens so strongly, under the pretext of love and affection towards that building, that he was united to Filippo as his colleague in the work. How great were the despair and the bitterness of Filippo, on hearing what the Wardens had done, may be seen from this, that he was minded to fly from Florence; and if it had not been for Donato and Luca della Robbia, who comforted him, he would have lost his reason. Truly impious and cruel is the rage of those who, blinded by envy, put into peril the honours and the beautiful works of others in their jealous emulation! It was no fault of theirs, in truth, that Filippo did not break his models into pieces, burn his designs, and throw away in less than half an hour all that labour which had occupied him for so many years. The Wardens at first made excuses to Filippo and exhorted him to proceed, saying that he himself and no other was the inventor and the creator of so noble a building; but at the same time they gave the same salary to Lorenzo as to Filippo. The work was pursued with little willingness on the part of Filippo, who saw that he must endure the labours that it entailed, and must then divide the honour and the fame equally with Lorenzo. Making up his mind, however, that he would find means to prevent Lorenzo from continuing very long in the work, he went on pursuing it in company with him, in the manner suggested by the writing given to the Wardens. Meanwhile, there arose in the mind of Filippo the idea of making such a model as had not yet been made; wherefore, having put his hand to this, he had it wrought by one Bartolommeo, a carpenter, who lived near the Studio. In this model, which had all the exact proportions measured to scale, he made all the difficult parts, such as staircases both lighted and dark, and every sort of window, door, tie, and buttress, together with a part of the gallery. Lorenzo, hearing of this, wished to see it, but Filippo refused to let him, whereupon he flew into a rage and ordered another model to be made for himself, to the end that he might not appear to be drawing his salary for nothing and to be of no account in the work. With regard to these models, Filippo was paid fifty lire and fifteen soldi for his, as we see from an order in the book of Migliore di Tommaso, dated October 3, 1419, whereas three hundred lire are entered as paid to Lorenzo Ghiberti for the labour and expense of his model, more in consequence of the friendship and favour that he enjoyed than of any profit or need that the building had of it.
This torment lasted before the eyes of Filippo until 1426, the friends of Lorenzo calling him the inventor equally with Filippo; and this annoyance disturbed the mind of Filippo so greatly that he was living in the utmost restlessness. Now, having thought of various new devices, he determined to rid himself entirely of Lorenzo, recognizing that he was of little account in the work. Filippo had already raised the cupola right round, what with the one vault and the other, to the height of twelve braccia, and he had now to place upon them the ties both of stone and of wood; and as this was a difficult matter, he wished to discuss it with Lorenzo, in order to see if he had considered this difficulty. And he found Lorenzo so far from having thought of such a matter, that he replied that he referred it to Filippo as the inventor. Lorenzo's answer pleased Filippo, since it appeared to him that this was the way to get him removed from the work, and to prove that he did not possess that intelligence which was claimed for him by his friends, and to expose the favour that had placed him in that position. Now the masons engaged on the work were at a standstill, waiting to be told to begin the part above the twelve braccia, and to make the vaults and bind them with ties. Having begun the drawing in of the cupola towards the top, it was necessary for them to make the scaffoldings, to the end that the masons and their labourers might be able to work without danger, seeing that the height was such that merely looking down brought fear and terror into the stoutest heart. The masons and the other master-builders were standing waiting for directions as to the ties and the scaffoldings; and since no decision was made either by Lorenzo or by Filippo, there arose a murmuring among the masons and the other master-builders, who saw no signs of the solicitude that had been shown before; and because, being poor people, they lived by the work of their hands, and suspected that neither one nor the other of the architects had enough courage to carry the work any further, they went about the building occupying themselves, to the best of their knowledge and power, with filling up and finishing all that had as yet been built.
One morning Filippo did not appear at the work, but bound up his head and went to bed, and caused plates and cloths to be heated with great solicitude, groaning continually and pretending to be suffering from colic. The master-builders, who were standing waiting for orders as to what they were to do, on hearing this, asked Lorenzo what they were to go on with: but he replied that it was for Filippo to give orders, and that they must wait for him. There was one who said, "What, dost thou not know his mind?" "Yes," answered Lorenzo, "but I would do nothing without him"; and this he said to excuse himself, because, not having seen the model of Filippo, and having never asked him what method he intended to follow, he would never commit himself in talking of the matter, in order not to appear ignorant, and would always make a double-edged answer, the more so as he knew that he was employed in the work against the will of Filippo. The illness of the latter having already lasted for more than two days, the provveditore and many of the master-masons went to see him and asked him repeatedly to tell them what they were to do. And he replied, "You have Lorenzo, let him do something"; nor could they get another word out of him. Whereupon, this becoming known, there arose discussions and very adverse judgments with regard to the work: some saying that Filippo had gone to bed in his vexation at finding that he had not the courage to raise the cupola, and that he was repenting of having meddled with the matter; while his friends defended him, saying that his anger, if anger it was, came from the outrage of having been given Lorenzo as colleague, but that his real trouble was colic, caused by fatiguing himself overmuch at the work. Now, while this noise was going on, the building was at a standstill, and almost all the work of the masons and stone-cutters was suspended; and they murmured against Lorenzo, saying, "He is good enough at drawing the salary, but as for directing the work, not a bit of it! If we had not Filippo, or if he were ill for long, what would the other do? Is it Filippo's fault that he is ill?" The Wardens of Works, seeing themselves disgraced by this state of things, determined to go and find Filippo; and after arriving and sympathizing with him first about his illness, they told him in how great confusion the building stood and what troubles his illness had brought upon them. Whereupon Filippo, speaking with great heat both under the cloak of illness and from love of the work, replied, "Is not that Lorenzo there? Can he do nothing?