I would distinguish debugging from logging.

That's not strictly true.  I often encounter problems that are best debugged by doing logging.

One example is if I'm tracking data during CGI script processing.  It wouldn't be appropriate to display the results to the generated HTML page, but adding a simple mechanism to log the results, behind-the-scenes, can be a lifesaver.

So "logging" in the sense that I'm using it is merely another way of saying "writing data to a logfile".

Update:  osunderdog, your good points (below) are well-taken.  I was mainly clarifying my slightly different usage of the word "logging".  Simply put, logging data to a file can be an aid to debugging.  But I see your distinction between the interaction you get with a debugger vs. the "post-mortem" aspect of perusing a logfile, after the fact.