As part of my broader project of promoting rationality widely, I'm going to work on making rationality-themed merchandise with slogans. I'd appreciate any ideas on what slogans would be short (5 words or less), engaging, and accessible, and appealing for both aspiring rationalists and smart youth and young adults who are just starting to learn about rationality. As an example, slogans like "Growing Mentally Stronger" or "Updating My Beliefs" are good, but "Tsuyoku Naritai!" is not, however much I personally like that slogan.
One of the key cultural values seems to be to be happy to be shown wrong and willing to change one's mind when presented with good information. Having clothing that signals that value would be nice.
From my perspective good merchandise would likely display institutational loyality. In your case the Intentional Insight logo looks well suited for that purpose.
The first set of rationality-themed merchandise is ready! Thanks for your suggestions :-)