end in itself

end in itself

A purpose or goal desired for its own sake (rather than to attain something else). For example, For me, writing books is an end in itself; they don't really make that much money. This expression employs the noun end in the sense of "final cause or purpose," a usage dating from the early 1500s.
See also: end, itself
References in classic literature ?
Every man's work, pursued steadily, tends in this way to become an end in itself, and so to bridge over the loveless chasms of his life.
This inalienable habit of saving, as an end in itself, belonged to the industrious men of business of a former generation, who made their fortunes slowly, almost as the tracking of the fox belongs to the harrier,--it constituted them a "race," which is nearly lost in these days of rapid money-getting, when lavishness comes close on the back of want.
The translation of morality into the metaphysical, as force, cause, end in itself, was HIS work.
She had accepted it as a place to live in, as an end in itself.
The ever-present danger is that technical expertise becomes an end in itself.