In the section entitled, “On the highest moral-physical good,” in the conclusion to the Part One of his Anthropology from a Pragmatic Point of View, Kant argues that good living and true humanity can be realized by having a good meal in good company. He also lays out his rules for a dinner party:
Number of guests: According to Kant, the number of guests should be such that the dinner party’s atmosphere is conducive for holding a good conversation. He recommends no fewer than three and no more than nine guests.
Flow of conversation: Kant says that extended silence should never be allowed at the dinner table. The topics on which everyone is interested must be selected for conversation, and the direction of conversation should not be changed unnecessarily because nothing good can be achieved when the guests are jumping from one topic to another.
Avoid dogmatism: Kant holds that it is the duty and responsibility of every guest to show respect for others by conversing in a respectful and benevolent manner. He prohibits the guests from being dogmatic. In Anthropology, he says: “Do not tolerate the beginning or continuation of anything dogmatic.”
A refreshing play of thoughts: Kant says that dinner parties have the potential for intellectual stimulation. The host and the guests can create a refreshing play of thoughts by picking up the important new stories of the day as the topic and having a back and forth argument and finally ending the conservation with humor.
Secrecy: Kant believes that there is some kind of a moral sanctity to any dinner party. If anything indiscreet gets said at the dinner party it should stay within the party. Most human beings, Kant says, find it prudent to conceal their political views, and it is the purpose of a dinner party to serve as an oasis of trust. A free exchange of ideas becomes possible when the host and guests respect one another’s privacy.
Choice of food: Kant says that while it is impossible to have universally valid judgements on food and drink, it is possible for a host to reach comparatively universal validity. He writes, “The host makes his decisions with the tastes of his guests in mind, so that everyone finds something to his own liking; such a procedure yields a comparatively universal validity.”
Moderate drinking: Kant supports drinking at dinner parties but only in moderation. He prefers wine to other drinks. He writes: “Drink loosens the tongue. But it also opens the heart wide, and it is a vehicle instrumental to a moral quality, that is, openheartedness.” However, some biographies claim that on occasions Kant drank so much red wine that he found it difficult to walk back to his home.
No music: Kant equates music with debauchery and is against having music at his dinner parties.
In Kant: Observations on the Feelings of the Beautiful and Sublime ad Other Writings, Patrick Frierson and Paul Guyer point out that Kant was not a dour ascetic during his younger days. Here's an excerpt from the book's Introduction:
[Immanuel Kant’s early works] show a Kant who is younger, more empirical, more playful and more romantic than the Kant who would emerge over the next several decades. In fact, starting with the Russian occupation of Königsberg in 1758 Kant attended regular dinner parties, and his elegance and wit earned him the title “the life of the party.” Kant had friends from a wide variety of social classes and regularly attended dinners and parties with military officers, bankers, merchants, noblemen and noblewomen. During this period he even warns his young student Herder “not [to] brood so much over his books, but rather follow his own example.”