In The Book of the Courtier Castiglione regularly inveighs against fortune and its power to do us so much irreparable harm. In one particularly bitter passage he laments how fortune uplifts to the skies whom she pleases while at the same time burying in the depths those most worthy of being exalted.

In due course, The Book of the Courtier was placed on the Index, a list of heretical books banned by the Catholic Church, for attributing so much power to what was, in effect, a pagan deity. Indeed, it's notable just how few references there are in the book to the Church. This is entirely in keeping with the humanist spirit of the age, which arose out of the rediscovery of pagan learning.

Although Castiglione assigns to fortune such an important role in the arrangement of human affairs, that does not mean that the ideal prince is entirely helpless in the face of such an overwhelming power. By the cultivation of virtue—ably assisted, of course, by a wise courtier—he can fortify himself to a considerable extent against the ups and downs of life, so that when his fortunes take a sharp downturn, as they inevitably will, he will be better able to deal with the consequences.

References to fortune are quite frequent in Baldassare Castiglione’s work The Book of the Courtier. In one translation, there are 33 such references in all (see link below). Choosing a representative passage is therefore difficult, and this difficulty is compounded by the fact that The Book of the Courtier consists of dialogues presenting varied points of view on various issues.

A review of the reference to fortune in The Book of the Courtier suggests, however, that Castiglione tended to present fortune as most Renaissance authors do: as something unpredictable, often unfair, and totally random. Renaissance thinkers tended to believe that fortune could not be controlled; all that could be controlled was one’s reactions to fortune. Ideally, a person was expected to be able to deal with both good and bad fortune by showing self-control, good judgment, reason, and restraint. Good fortune should not cause pride; bad fortune should not cause despair. Instead, persons should try to live their lives as virtuously as possible, without being unduly affected either by prosperity or by adversity. This kind of balanced, sensible, reasonable approach to fortune was especially valuable in a courtier, who was more likely even than most people to experience sudden changes in fortune.

One passage in The Book of the Courtier that exemplifies some of the ideas just described is this one:

Yet cheeflye in warr is much set by that true manlines, which maketh the minde voide from all passions, so that he not onlye feareth not perilles, but passeth not upon  them. Likewise steadfastnesse, and pacyence, abidinge with a quiet and untroubled minde  all the strokes of fortune. It is beehouffull likewise in warr and at all other times to have  all the vertues that beelonge to honestye, as justice, staidnesse, sobermoode: but muche  more in peace and rest, because often times men in prosperitie and rest, whan favourable fortune fauneth upon them, wexe unrighteous, untemperate, and suffre themselves to be corrupted with pleasures.

In this passage, the speaker clearly celebrates patience, reason, and self-control, no matter what kind of fortune a person experiences.  This was by far the most typical teaching about fortune to be found in many Renaissance texts, including The Book of the Courtier.