This is the statue of the chevalier Lefebvre de la Barre, a young Frenchman, tortured and beheaded because he refused to take off his hat to honor a religious procession.
I came across this statue on our trip to Paris a few months back. It can be found close to the Sacré-Cœur – although I suspect most tourists pass it by without glancing at it once.
The moral of this story ? Better take of your hat when zealots walk by.