The phrase "rational people" refers to individuals who think logically, use reason, and make sensible decisions based on information and evidence, rather than emotions or beliefs. Full definition
Free agency is an irrational auction run by rational people who get sucked into the irrational. (sbnation.com)
But the real meat of the story might be how religion and the need to belong to something can make the most rational person do horrible things. (tomsguide.com)
The reason rational people do not believe in god is because there is no way to prove that god exists. (religion.blogs.cnn.com)