De peste quaestiones duae explicatae

And is it therefore not contagious? Or does one single prostitute not rather infect many with this plague, who in turn contaminate one another, to such an extent that this most disgraceful disease is contracted not only from intercourse but also from breath and touch? And it is even sucked by infants from the breasts of nurses, and conversely, nurses who are suckling an infant conceived from an impure father or born from an impure mother contract this very same disgraceful disease. Therefore, those arguments are also of such a kind that they do not even require refutation. Certainly, it is absurd to think that as many plagues are immediately (as they say) sent to individual men, rather than that the species of disease itself exists, by which some infect others through contagion. For whether the Lord kills everyone with one wound, or, as happened to the Midianites, He strikes down whomever He has destined for death with wounds inflicted upon one another, what difference does it make? Nor again is there any difference in that matter which we are discussing, whether someone is struck down by the weapon of God himself or by the contagion of another.

5th Argument.

Let us now approach that which they mention regarding the secondary causes themselves, which they deny to be either any certain position of the stars or the corruption of the air.

Resp. 1.

Nor indeed do natural philosophers, as far as I understand, want all plague or contagion to arise from those causes.

Resp. 2.

But let us grant this, and let us pretend that all natural causes of the plague are those mentioned by them.