Today is World Logic Day! May all of your arguments be valid.

What do you get someone for World Logic Day? Your answers are welcome in the comments.

For those who don’t know, World Logic Day was declared a holiday in 2019 by the United Nations Educational, Scientific and Cultural Organization (UNESCO) and the International Council for Philosophy and Humanistic Studies (CIPSH). It’s celebrated every January 14th, which is both the birthday of Alfred Tarski and the date of Kurt Gödel’s death. [UPDATE: “They have stolen your baby”: see this comment from Jean-Yves Beziau for an account of how World Logic Day came into existence.]

According to UNESCO, “there is little public awareness of the importance of logic.” Apparently one of the traditions of World Logic Day is understatement.

I will admit that World Logic Day this year caught me by surprise, following, as it does, so closely after National Rubber Ducky Day (January 13th). But as soon as I remembered it, I jumped out of the bath, ate a pastrami sandwich, then dressed up my dog…

it was cold

…and (belatedly) started typing.

What does one do on World Logic Day? It may be too late to attend the celebrations this year, but Deniz Sarikaya (Vrije Universiteit Brussel), who works with CIPSH, wants us to start thinking about next year’s festivities. In an email he encourages individuals and groups to register their events in advance with CIPSH so they can be part of the official list of celebrations.

He also notes that there will be a World Logic Day graphic design contest leading up to next year:

Logic, traditionally seen as the domain of pure thought and reason, is notoriously difficult to visualize. Finding ways to express the most fundamental laws that govern the human process of reasoning without words and in pictures is a true challenge: we would love to see your attempts to overcome it. 

The theme of World Logic Day 2026 will be “Logic & Diversity,” and we would be particularly happy with submissions that focus on aspects that fit with the theme, e.g., the question of whether there is one true logic or several, the question of whether logical systems can be in conflict with each other, etc. We encourage creative interpretations, reflecting on how logic interacts with the rich tapestry of diverse cultures, perspectives, and ideas.

Further details on the contest are here.

Stay sound out there, people.