The discovery of a world in the moone

by John Wilkins

But now if any question what they doe for a Moone who live in the upper part of her body? I answer, the solving of this is the most uncertaine and difficult thing that I know of concerning this whole matter. But yet I will give you two probable conjectures.

1. Perhaps, the upper Hemispheare of the Moone doth receive a sufficient light from those planets about it, and amongst these Venus (it may be) bestowes a more especiall brightnesse, since Galilæus hath plainly discerned that she suffers the same increase and decreases, as the Moone hath, and ’tis probable that this may be perceived there without the help of a glasse, because they are farre neerer it than wee. When Venus (saith Keplar) lies downe in the Perige or lower part of her supposed Epicycle, then is she in conjunction with her husband the Sunne, from whom after she hath departed for the space of ten moneths, shee gets plenum uterum, and is in the full.[7]

But you’ll reply, though Venus may bestow some light when she is over the Moone, and in conjunction, yet being in opposition, she is not visible to them, and what shall they then doe for light?

I answer, then they have none: nor doth this make so great a difference betwixt those two Hemispheares as there is with us, betwixt the places under the poles, and the line, but if this bee not sufficient, then I say in the second place that

2. Perhaps there may be some other enlightened body above the Moone which we cannot discerne, nor is this altogether improbable because there is almost the like observed in Saturne, who appeares through this glasse with two lesser bodies on each side, which may supply the office of Moones, unto each hemispheare thus:

So in this world also there may be some such body, though wee cannot discerne it, because the Moone is alwaies in a streight line, betwixt our eye and that. Nor is it altogether unlikely that there should bee more moones to one Orbe, because Jupiter also is observed to have foure such bodies that move round about him.

But it may seeme a very difficult thing to conceive, how so grosse and darke a body as our earth, should yeeld such cleare light as proceedes from the Moone, and therefore the Cardinall de Cusa De doct. ig. l. 2. c. 12. (who thinkes every Starre to be a severall world) is of opinion that the light of the Sunne is not able to make them appeare so bright, but the reason of their shining is, because wee behold them at a great distance through their regions of fire which doe set a shining lustre upon those bodies that of themselves are darke. Vnde si quis esset extra regionem ignis, terra ista in circumferentia suæ regionis per medium ignis lucida stella appareret.

So that if man were beyond the region of fire, this earth would appear through that as a bright Starre.

But if this were the onely reason then would the Moone bee freed from such increases and decreases as shee is now lyable unto.