Desiderata, (that which is to be desired) it's a poem, a list of desirable items, written by Max Ehrmann, in 1927 at the ripe old age of 55. It made him famous but only after his death. He captured the essence of being, and the correct way of living in such neat and concise prose.
Nimoy wasn't the only one to use it, many others used it, including Prime Minister Trudeau in 1972 during his Canadian Federal Election campaign. Morgan Freeman said the poem helped shape his life.
Supposedly the poem was found in old Saint Paul's Church, mislabeled as written in 1692. For what reason no one knows.
Here's the poem is in it's entirety, enjoy...