[Two states in the history of the concept of contagion: from Hippocrates to Galen].

The Hippocratic doctor does not believe any more in magico-religious "miasmata" that pollute whole populations; he accuses the environmental air, thus freeing his fellow-men from the fear of gods' wrath but impeding the rise of the concept of contagion and disconnecting his own experience from the vet's. Galen however observing a few cases of lepra in Minor Asia intuits human contagion.