I have always been thought you should have a quite leg, but only be active with it when you need it. Your seat should be your primary aide.
Can someone please explain?
I have linked to a video of a for sale horse I was looking at to show what I am talking about. I can't help but watch her and think she is influencing her horse somehow with her leg (including that she is using spurs)
However, I have seen Grand Prix Dressage riders with the same lower leg.