The principle of happiness may, indeed, furnish maxims, but never such as would be competent to be laws of the will, even if universal happiness were made the object.
 Immanuel Kant, Critique of Practical Reason (1788). copy citation

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Author Immanuel Kant
Source Critique of Practical Reason
Topic happiness law
Date 1788
Language English
Reference
Note Translated by Thomas Kingsmill Abbott
Weblink http://www.gutenberg.org/cache/epub/5683/pg5683-images.html

Context

“The few remarks that follow may appear superfluous where the truth is so plain, but at least they may serve to give a little more distinctness to the judgement of common sense.
{BOOK_1|CHAPTER_1 ^paragraph 95}
The principle of happiness may, indeed, furnish maxims, but never such as would be competent to be laws of the will, even if universal happiness were made the object. For since the knowledge of this rests on mere empirical data, since every man's judgement on it depends very much on his particular point of view, which is itself moreover very variable, it can supply only general rules, not universal; that is, it can give rules which on the average will most frequently fit, but not rules which must hold good always and necessarily; hence, no practical laws can be founded on it.” source