The Extraterrestial Error

Are aliens heresy? Ita videtur!

Th error of Zanini de Solcia, condemned in Cum sicut by Pius II:

"That God created another world than this one, and that in its time many other men and women existed and that consequently Adam was not the first man.”

Furthermore, one of the errors Giordano Bruno was condemned for was holding that there is a plurality of worlds.

Humani Generis condemned Polygenism.

But maybe they aren’t men? Well no. If they’re rational animals, they are humans. 

Fr. Garrigou-Lagrange:

“Some men seem to be of the opinion that on other heavenly bodies perhaps there are rational animals of another species than man. But this seems to be false, for the term “rational animal” seems to be not a genus but the ultimate species, according to the principle of continuity; for the highest in the lowest order, for instance, the sensitive life, touches the lowest in the highest order, namely, the intellective life. Hence there is no conjunction of the highest in the sensitive life with the lowest in the intellective life, except in one species, and this is not susceptible to either increase or decrease.”