A wander through the many Facebook groups, YouTube videos, and Twitter tweeters with atheism as their central subject matter will see many atheists and sceptics making the claim of being rational.  One could also look at the ‘memeosphere’ centred around atheism and scepticism to see images making claims like ‘I am a sceptic/atheist because I am rational’, and other similar memes.  What does it mean to be rational though?  That is a rather large question, and involves many questions about......