In 1487 Leonardo wrote to the Works Department of the Cathedral of Milan to recommend himself as the best man to supervise certain repairs and improvements to the cathedral that were under consideration. Here, Leonardo’s approach was very different from the one he employed in his 1483 appeal to the duke of Milan (see “Document 15.3: Leonardo to Ludovico Sforza, Duke of Milan”). His letter to the Works Department begins with an extended analogy between medicine and architecture, displaying not Leonardo the weapons maker, but Leonardo the humanist. As you read, consider why Leonardo gave particular emphasis to his familiarity with the principles of classical architecture and his knowledge of the intentions of the cathedral’s original architect.
My Lords, Father Deputies, just as for doctors, guardians, nurses it is necessary that they should understand what man is, what life is, what health is, and how it is maintained by a balance and harmony of elements, while a discord of these is its ruin and undoing; and one with a good knowledge of these conditions will be better able to repair than one who is without it.
You know that medicines when well used restore health to the sick; and they will be well used when the doctor together with the understanding of their nature shall understand also what man is, what life is, what constitution is and what health is. Understanding these well he will also understand well their opposites and when this is the case he will know well how to repair. . . .
You know that medicines well used restore health to the sick, and he who knows them well will use them well if he also understands what man is, and what life and the constitutions are, and what health is. Knowing these well he will know their opposites, and being thus equipped he will be nearer a cure than anyone else. The need of the invalid cathedral is similar — it requires a doctor architect who well understands what an edifice is, and on what rules the correct method of building is based, and whence these rules are derived and into how many parts they are divided, and what are the causes that hold the structure together, and make it last, and what is the nature of weight, and what is the desire of force and in what manner they should be combined and related, and what effect their union produces. Whoever has a true knowledge of these things will satisfy you by his intelligence and his work. . . . Therefore I shall try without detracting and without abusing anyone, to satisfy you partly by arguments and partly by works, sometimes revealing the effects from the causes, sometimes the reasoning by experiment, . . . fitting with them certain principles of ancient architects and the evidence of buildings they constructed and what were the reasons of their ruin or their survival, etc.
And I shall show at the same time what is the first law of weight and what and how many are the causes that bring ruin to buildings and what is the condition of their stability and permanence. But in order not to diffuse to your Excellencies, I will begin by the plan of the first architect of the cathedral and show clearly what was his intention as revealed by the edifice begun by him, and having understood this you will be able clearly to recognize that the model which I have made embodies that symmetry, that harmony and that conformity, which belongs to the building already begun: what is an edifice, and wherefrom do the rules of correct construction derive their origin, and what and how many are the parts that belong to these.
Either I, or others who can expound it better than I, choose him, and set aside all partialities.
Source: Leonardo da Vinci, Notebooks, 2d ed., edited by Thereza Wells (2008), 525w from pp. 281–
Questions to Consider