R' Joel Rich asked:
> Was there ever a post-sanhedrin period where this
> position would have a nafka-mina (i.e. 1 universally
> recognized authority)?

R' Micha Berger answered:
> If I agreed with your understanding of the Chinukh, how
> about Ravina veRav Ashi and the geonim?

In what way would "Ravina veRav Ashi and the geonim" constitute ONE 
authority?

And if RMB would amend that answer to simply "Ravina veRav Ashi", 
i.e., Talmud Bavli, then I'd ask, "Aren't there cases where we pasken 
like the Yerushalmi against the Bavli?" (not that I can think of any 
offhand, but I'm pretty sure I've heard of the phenomenon)

Akiva Miller