What is the full sentence?

Hi, Linguamama,

@Linguamama posted:

Different from the ancient Greeks, who saw leisure as an opportunity for well-rounded development, Romans perceived leisure to be primarily rest from work.

I think the best paraphrase is #1:

@Linguamama posted:

#1. Romans perceived leisure to be primarily rest from work, which was[is] different from the ancient Greeks, who saw leisure as an opportunity for well-rounded development.

The problem with #2:

@Linguamama posted:

#2. Romans, who were[are] different from the ancient Greeks, who saw leisure as an opportunity for well-rounded development, perceived leisure to be primarily rest from work.

lies in the fact that the difference lay in their conception of leisure, and the way #2 is expressed (apart from the convoluted succession of two who-clauses) points to Romans and Greeks being different in general rather than in their vision of leisure, which is what the original text conveys.

A good alternative would be:

- Unlike the ancient Greeks, who saw leisure as an opportunity for well-rounded development, Romans perceived leisure to be primarily rest from work.

On page 696 of their Comprehensive Grammar of the English Language, Quirk et al suggest that "unlike," defined under page 667 of the same book as a preposition of manner, has a clausal rather than an adjectival meaning:

Unlike is used with the meaning of negative resemblance 'not like':

Unlike his brother (who writes poetry), Bill writes science fiction.
Bill writes science fiction, unlike his brother (who writes poetry).

The predicative use of unlike would be possible if an "in that"-clause were added, but the result would be too wordy to avoid ambiguity:

- Bill is unlike his brother in that the former writes science fiction / in that the latter writes poetry.

A similar revision would be required to fix #2:

- Romans, who were different from the ancient Greeks in that these saw leisure as an opportunity for well-rounded development, perceived leisure to be primarily rest from work.