"Think Only What Concerns Thee And Thy Being"
Context: When Raphael has finished his story of the creation of the world, Adam asks him why the earth, which is such a tiny sphere in comparison with the rest of the universe, is served by so many planets and stars that revolve about it at such an incomprehensible speed. Adam is, of course, referring to the Ptolemaic system of astronomy: according to it, the earth is motionless and the rest of the cosmos revolves around it. He says that it would be more economical to have the earth revolve and the rest of the astral bodies remain still. At this point Eve, who has listened to the angel's story, removes herself from the scene to go about her work, not that she cannot comprehend Raphael, but because it will be pleasanter to have Adam explain matters when the two of them are alone. Raphael says that Adam does well to question these things, but the great Architect made things as he wanted them, and he will be amused at men's explanations of them. He says that the earth, though perhaps small and dark, is more important than larger and brighter bodies, as large size and brightness are not necessarily signs of great value. He asks a number of rhetorical questions about the constitution of the cosmos, the answers to which would indicate that the cosmos would work as well if the earth moved as it does with the astral bodies moving. Milton is here giving at least a nod of recognition to the Copernican system of astronomy, which was still a matter of debate in his time, more than a century after it had been published. Milton also hints his belief that the moon and innumerable other planets are inhabited.
But whether thus these things, or whether not,Whether the sun predominant in heavenRise on the earth, or earth rise on the sun,He from the east his flaming road begin,Or she from west her silent course advanceWith inoffensive pace that spinning sleepsOn her soft axle, while she so paces even,And bears thee soft with the smooth air along,Solicit not thy thoughts with matters hid,Leave them to God above, Him serve and fear;Of other creatures, as Him pleases best,Wherever placed, let Him dispose; joy thouIn what He gives to thee, this paradiseAnd thy fair Eve: heaven is for thee too highTo know what passes there; be lowly wise:Think only what concerns thee and thy being;Dream not of other worlds, what creatures thereLive, in what state, condition or degree,Contented that thus far hath been revealedNot of earth only but of highest heaven.