Sonnet 59 dwells on the paradox that what is new is always expressed in terms of what is already known. The elements of any invention or creative composition must be common knowledge, or old news. The phrase "laboring for invention" indicates not only the poet's determination to create something entirely new in his verse but also his frustration in trying to do so.
Once again questioning the worth of his sonnets, the poet longs for the chance to read verse written about beauty such as the young man's "Even of five hundred courses of the sun." He wants to judge his sonnets against those of antiquity — "the old world" — to determine if he is simply rehashing what has already been written about beauty. But even more than this, he wants to confirm that his sonnets are as good, if not better, than other poetry whose subject is beauty. He ends stating that he's certain that previous writers have given high praise to lesser subjects than the beautiful youth.