Full Idea
Let us think this thought in its most terrible form: existence as it is, without meaning or goal, but inevitably recurring, without any finale into nothingness: 'eternal recurrence'.
Gist of Idea
Existence without meaning or goal or end, eternally recurring, is a terrible thought
Source
Friedrich Nietzsche (Writings from Late Notebooks [1887], 05[71].6)
Book Reference
Nietzsche,Friedrich: 'Writings from the Late Notebooks', ed/tr. Bittner,Rüdiger [CUP 2003], p.118
A Reaction
I take this in a positive spirit - that if you wish to live well you should create a life which you could endure and enjoy, even if it recurred eternally. But that might be rather conservative rather than exciting, if we always avoided giving offence.