Januarius de Concilio was a Catholic priest and professor who argued for the ubiquity of extraterrestrial life on theological grounds. In an 1884 article, he wrote:

 

[A]s there is an immense distance between the highest intellect of mankind and that of the lowest pure spiritual substances, the cosmological law of affinity demands that there should be some intermediate species to soften down the immense contrast ...

 

These intermediate species, he suggests, are the inhabitants of other worlds. Life, in his view, must exist everywhere since a sterile planet would be a waste of God's powers. On the difficult question of Christ's incarnation and redemption he asserts that, although it happened only once, on Earth, its effect must extend to all other "species of incorporated intelligences [which] may have fallen, and very likely did fall ..."