Here's the Conclusion paragraph, which I don't think does justice to the depth of the work. it's written as if the Stoics were an and advance in a proper direction from the Epicurean viewpoint. As you would expect, I think that the reverse is true - the Stoics went on a rabbit hunt that totally threw away the trail that Epicurus had pointed out. I would say that the reason that Epicurus did not "propose a positive theory of universals as concepts" is that Epicurus would have held this to be error. the mind alone does not make a rose a rose.
I think the details of the article are excellent in pointing to what Epicurus actually proposed it is that makes a rose a rose. To repeat a comment from earlier in the thread, Epicurus' way of looking at things may be foreign to us but that doesn't make it wrong. And the current world may be so caught up in Platonism and rationalism that "concepts" and 'conceptualism" are the be-all end-all of all analysis, but that doesn't make it correct, and that doesn't make Epicurus wrong. Had Epicurus in fact "proposed a positive theory of universals as concepts" - if in fact he had been a "nominalist" in that sense - he would have been violating his own premises, and I think Epicurus would reject that direction out of hand. A rose is a rose whether we assign it that name or not. The tree that falls in the forest when no one is around does make a sound. And I am also firmly convinced that we do not determine whether the cat is dead or alive by looking at it. All of these seem to me to be related issues that deserve much clarification.
And they deserve clarification and discussion early in the process of studying Epicurus! This is something that needs to be hammered out in preparation for elementary school lessons - otherwise we spend a lifetime never really grasping where Epicurus was going.
Quote.4. Conclusion
The comparison between the Stoic and the Epicurean criticism of Platonic ontology shows the difference between elimination and con-version of the Ideas into an ontological system which, on both accounts, denies the existence of supra-sensible items. The different forms their reactions take on, marks the difference between the Stoic view about bodies as existing and incorporeals as subsisting, and the Epicurean view that body and void alone exist. However, both accounts meet in rejecting the Ideas from reality, considering generic items to be de-pendent, to varying degrees, on the workings of the mind. With the theory of preconceptions, the Epicureans move towards a basic form of conceptualisation of reality, but it is the Stoics, with their concern with genera and species who propose a positive theory of universals as concepts.