I will arrive from Bruge and would like to know how long I need to catch the train on the Thalys train system. I arrive on track 15. Thank you for your help.
Cheryl

I would reserve 30 minutes for the transfer, just to be on the safe side.

Emro2
thank you--I have 33 min would it be wise to take a earlier train from Bruge.

Emro2 is being very conservative. 30 minutes is plenty of time. I would be comfortable with 10 mins, unless there are some special circumstances (someone with mobility problems, for example). The Gare du Midi is neither enormous nor complicated.

33 min is ok as transfer time
No real need for an earlier train, if yours is on time.

When you miss the connecting Thalys you migth have to buy a new Thalys-ticket depending on type of ticket.
That is why I prefer at least the half hour.

(If it were a normal train I wouldn't worry because you could just take the next one.)

Unfortunately the area directly around the station 'Bruxelles Midi/Brussel-Zuid' is in contrast to Antwerp Central station not very interesting.