The Gemara [Ksubos 86] says that we force [כופין] a person to fulfill mitzvos - like it or not!
But according to the opinoin that מצוות צריכות כוונה it won't help to force the person b/c he doesn't have כוננה to be yotzei. You can coerce a מעשה - you can't coerce a כוונה??!!!
[This is a big rule in therapy. We are not always free to determine our circumstances but we are free in determining our attitudes. Toiras Viktor Frankel].
