Pliny, Natural History 2.1:
“Of this world and this sky (whatever it may be right to call it under another name) under whose arch all things pass, it is enough to believe that they are the divine will, eternal, measureless, neither created nor susceptible to destruction. Searching for things outside of this realm is neither the business of humans, nor does the human mind’s power of inference extend so far. It is sacred, eternal, all in all, or rather, itself the whole sum of being, unbounded and similar to something bounded, sure of all things and yet similar to something uncertain, embracing all things outside within itself, the work of the nature of things and itself the very nature of them.
It is madness that some have wrangled with the measure of the world in their minds and dared to publish it, while others have taken that as an occasion for claiming that there are innumerable worlds, so that one could believe that there are as any natures of the world, or, if one nature produced them all, that there are as many suns and moons and in each one other immense and innumerable stars. It is as if the same questions would not occur to our thought every time at the end from our desire of finishing them, or, if this infinity of nature could be assigned to the artificer of all things, it is as if that same thing could not be understood in one idea, especially in such a great work as our world.
To be sure, it is madness – madness! – to go beyond the world and, as if all of the things within it were already plainly known, to investigate what lies outside it as though one could take the measure of anything when they do not know the measure of themselves, or as if the mind of a human could take in what even the world itself cannot contain.”
mundum et hoc quodcumque nomine alio caelum appellare libuit, cuius circumflexu degunt cuncta, numen esse credi par est, aeternum, inmensum, neque genitum neque interiturum umquam. huius extera indagare nec interest hominum nec capit humanae coniectura mentis. sacer est, aeternus, immensus, totus in toto, immo vero ipse totum, infinitus ac finito similis, omnium rerum certus et similis incerto, extra intra cuncta conplexus in se, idemque rerum naturae opus et rerum ipsa natura. furor est mensuram eius animo quosdam agitasse atque prodere ausos, alios rursus occasione hinc sumpta aut hic data innumerabiles tradidisse mundos, ut totidem rerum naturas credi oporteret aut, si una omnes incubaret, totidem tamen soles totidemque lunas et cetera etiam in uno et inmensa et innumerabilia sidera, quasi non eaedem quaestiones semper in termino cogitationi sint occursurae desiderio finis alicuius aut, si haec infinitas naturae omnium artifici possit adsignari, non idem illud in uno facilius sit intellegi, tanto praesertim opere. furor est profecto, furor egredi ex eo et, tamquam interna eius cuncta plane iam nota sint, ita scrutari extera, quasi vero mensuram ullius rei possit agere qui sui nesciat, aut mens hominis videre quae mundus ipse non capiat.