Full Idea
Happiness is the condition of a rational being in the world with whom everything goes according to his wish and will.
Gist of Idea
Happiness is the condition of a rational being for whom everything goes as they wish
Source
Immanuel Kant (Critique of Practical Reason [1788], I.II.II.V)
Book Reference
Kant,Immanuel: 'Critique of Practical Reason (Third edition)', ed/tr. Beck,Lewis White [Library of Liberal Arts 1993], p.131
A Reaction
For such a sophisticated and rational philosopher this seems a rather crude notion. Reluctant alcoholics don't fit. Bradley has a much better definition (Idea 5655).
Related Idea
Idea 5655 Happiness is not satisfaction of desires, but fulfilment of values [Bradley, by Scruton]