How to select from table by comparing multiple rows with same key

The question is which of the pdates for a module do you want to use for ordering purposes?

If you are happy to use the largest, you could use:

select module from logging order by max(pdate); 

--- EDIT

I think I get it now - you probably want something like this:

select module
from( select module, 
             sum(module_step) over (order by pdate rows unbounded preceding) 
                 as batch_number, 
             pdate
      from( select module, 
                   case lag(module) over (order by pdate) when module then 0 
                        else 1 end as module_step, 
                   pdate from logging) )
group by module, batch_number
order by batch_number;

a company may have both an inactive and an active account in M

SO I assume it can be only one active and one inactive row. Here is a solution with JOINs only. If there can be multiple (active) rows, you should use EXISTS instead, as @ypercube already mentioned in his comment.

SELECT R.*, M1.active
FROM   R
JOIN   M AS M1 ON M1.company = R.company
              AND M1.account = R.account
              AND M1.active  = 'inactive'
LEFT   JOIN M AS M2 ON M2.company = R.company
                   AND M2.account = R.account -- or no active account at all?
                   AND M2.active  = 'active'
WHERE  M2.company IS NULL;

As @ypercube commented: it did not become entirely clear whether you don't want any active account to invalidate the company or just a matching active account.

I went with matching account in my query. Remove AND M2.account = R.account from the JOIN condition if you want any.