Success

Success is counted sweetest
By those who ne'er succeed.
To comprehend a nectar
Requires sorest need.

Not one of all the purple host
Who took the flag to-day
Can tell the definition,
So clear, of victory,

As he, defeated, dying,
On whose forbidden ear
The distant strains of triumph
Break, agonized and clear!

To laugh often and much;
To win the respect of intelligent people and the affection of children;
To earn the appreciation of honest critics and endure the betrayal of false friends;
To appreciate beauty, to find the best in others;
To leave the world a bit better, whether by a healthy child, a garden patch or a redeemed social condition;
To know even one life has breathed easier because you have lived.
This is to have succeeded.

Although this is often attributed to Ralph Waldo Emerson, it is unlikely that he is the source of this work (and it doesn't sound like his poetry either).

First off, none of the word sequences appear in any of Emerson's works. It is possible to search for them at http://www.emersoncentral.com/search.htm, and your result will be the same as mine - nothing (though, if you search the web, you will find dozens of references to it attributing it to Emerson. I even found this quote on a card.).

There is evidence that this dates back to 1905 by Bessie Stanley with the poem:

He has achieved success who has lived well,
  laughed often and loved much;
who has enjoyed the trust of pure women,
the respect of intelligent men and the love of little children;
who has filled his niche and accomplished his task;
who has left the world better than he found it,
  whether by an improved poppy, a perfect poem, or a rescued soul;
who has never lacked appreciation of earth's beauty
  or failed to express it;
who has always looked for the best in others
  and given them the best he had;
whose life was an inspiration;
whose memory is a benediction.

It was submitted to the Brown Book Magazine in a contest in 1904 and was awarded a $250 cash prize.

However, even the printings of two local newspapers in 1905 with that poem do not agree (the one above is from the 1937 edition of Bartlett's Familiar Quotations. There is some suspicion that this is a paraphrasing of a previous quote from Robert Louis Stevenson, however this was published several years after his death (1894).

Our business in life is not to succeed, but to continue to fail in good spirits.

Whatever the case, and whoever wrote it - the ideas and feelings that it speak of are still as powerful as ever.

Suc*cess" (?), n. [L. successus: cf. F. succes. See Succeed.]

1.

Act of succeeding; succession.

Then all the sons of these five brethren reigned By due success. Spenser.

2.

That which comes after; hence, consequence, issue, or result, of an endeavor or undertaking, whether good or bad; the outcome of effort.

Men . . . that are like to do that, that is committed to them, and to report back again faithfully the success. Bacon.

Perplexed and troubled at his bad success The tempter stood. Milton.

3.

The favorable or prosperous termination of anything attempted; the attainment of a proposed object; prosperous issue.

Dream of success and happy victory! Shak.

Or teach with more success her son The vices of the time to shun. Waller.

Military successes, above all others, elevate the minds of a people. Atterbury.

4.

That which meets with, or one who accomplishes, favorable results, as a play or a player.

© Webster 1913.