Darwin studied specific species of animals on the galapagos islands and other places, and observed
similar species in different areas with unique traits all birds have the same size beaks giant turtles live longer than other species because of their large hearts fossils hold the key to the past

you did not attach the discourse, but i assume it to be the discourse on the origin and basis of inequality among men (the original titile in french is: "discours sur l'origine et les fondements de l'inégalité parmi les hommes"), also know as "second discourse". in this discourse, jean-jacques rousseau emphasizes that private property is the basis of all inequalities.

therefore, what enabled the old regime to maintain as long as it did was private property.