Upbeat or Downbeat?

[schubertiad]

I'm learning Bach's f minor p+f from WTC II and am a little confused by the prelude. The piece is in 2/4 meter and starts on beat 2. While this would normally be the upbeat, with the strong beat coming at the start of bar 2, this supposed upbeat sounds very much like the main beat. When other thematic material comes in (i.e bar 16, bar 20) it is also on the last beat of the bar as opposed to the first. Why did Bach write it in this way? Do I try and play as written (which sounds a little strange to my ears) or do I just treat the upbeats as downbeats?
Edit: I just realized that people may have read the thread title and anticipated a witty subject. Sorry about that...

[richard black]

Play it as written! The beat only seems to be in the wrong place if you think the left hand is part of the melody, which it isn't. Getting the barring and phrasing right also helps combat the tendency to play this prelude too slowly.

[counterpoint]

Looking at the bass notes, it's neither up- nor downbeat. Just 8 quarter notes played in marcato style. Every quarter note gets an accent.

Funny how it ressembles to the theme of the Eroica Variations 

Looking at the notes of the right hand - the single 8th note is an upbeat of course.

[schubertiad]

Thanks for the responses. Richard, your comment about the left hand not belonging to the melody was spot on. It makes a lot more sense now. Thanks!

[sharon_f]

Great P&F, BTW. Check out Richter's recording.