I’ve already posed the question, I’d like to add two points. First, sustained economic growth in the Western world starts in 17th century England, as shown by Greg Clark. Interest in economic reasoning then comes rapidly, first from the mercantilists, then in Adam Smith and some earlier free trade thinkers, such as Dudley North and Nicholas Barbon.
Second, the idea of "private vices, publick virtues" was central for eighteenth century economic thought and for social science more generally. This came from Bernard Mandeville (drawing upon the French Jansenists) in 1720. It’s no accident that Mandeville lived in the Dutch Republic, which had very little censorship. No, I am not a Straussian but the merits of that viewpoint are often overlooked.
The School of Salamanca had an excellent marginal utility theory in 17th century Spain, the framework simply did not go anywhere. For that matter we can look later and see that Samuel Bailey, Mountifort Longfield (1834), and others had critical components of Marshall. But no one really cared because they could not yet see how important those contributions would turn out to be. This is a central theme in why the growth of economic thought took so long.
It also suggests that today we might have some very important ideas amongst us, we simply cannot yet see how fruitful they will be. Their own proponents may not even know it.