The Gay Science (German: Die fröhliche Wissenschaft) or The Joyful Wisdom is a book by Friedrich Nietzsche, first published in 1882 and followed by a second edition, which was published after the completion of Thus Spoke Zarathustra and Beyond Good and Evil, in 1886. This substantial expansion includes a fifth book and an appendix of songs. It was noted by Nietzsche to be "the most personal of all [his] books", and contains the greatest number of poems in any of his published works.
