Books · 1905
Happiness is the only sanction of life; where happiness fails, existence remains a mad and lamentable experiment.
— George Santayana • The Life of Reason, Vol. 1

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
Santayana says happiness is the only justification for living; where it fails, existence is a "mad and lamentable experiment." It's a philosopher's claim that life has to earn its keep through happiness, otherwise it looks like a badly conceived trial.
Context reviewed