If it's the solid gate, you need to defeat a critter down the road to get the key that unlocks the lever beside the gate.
If it's the energy gate, you need to activate the shrine sitting in the middle of the road. You may need to defeat some Elementals (if memory serves) and activate the shrines in their Dojos with the staff you assembled in an earlier quest.
You either need to light the brazier or you need to go down the other path, go into the dojo and fight that guy then light the dojo.
The reason why I'm not sure is that I didn't know what to do first either, so I killed the boss in the dojo then wandered around until I tried to light the brazier. Once lit the force field drops. But I do know for sure that you can't pull the lever to open the door until you defeat the guy in the dojo. Hope this helps.
