> I'm sorry to say that you're wrong here. 

I'm happy to be corrected.

It is fair to say I failed to take the multiple inheritance case into 
account. Clearly super can't *only* look at the MRO of the first object 
since that will miss the multiple inheritance case, as you point out. 
Thank you.

But neither can it *only* look at the MRO of the second class, because 
that would restart the search at the top of the hierarchy; also if 
type(second argument) was the only thing that mattered, that would make 
the first argument redundant and pointless.