FROM A STUDENT.....HE GETS THE IDEA!
"By the Law of Periodical Repetition, everything which has happened once must happen again, and again, and again -- and not capriciously, but at regular periods, and each thing in its own period, not another's, and each obeying its own law... The same Nature which delights in periodical repetition in the sky is the Nature which orders the affairs of the earth. Let us not underrate the value of that hint." - Mark Twain