I have always noticed that deeply and truly religious persons are fond of a good joke, and I am suspicious of those who aren’t.  The strain of solemnity becomes unbearable, because it is unnatural.‘  Whitehead then goes on to point out how the Athenians would show theatrical tragedies and satyrs in the same evening.

Later in the passage he discusses the necessity of irreverence and says:

Is it that nothing, no experience good or bad, no belief, no cause, is, in itself, momentous enough to monopolize the whole of life to the exclusion of laughter?  Laughter is our reminder that our theories are an attempt to make existence intelligible, but necessarily only an attempt, and does not the irrational, the instinctive burst in to keep the balance true by laughter?

Later in the book Whitehead says, ‘Laughter is a divine attribute.’