No rancor necessary, no debate required. It’s over, and in an honest moment on a reflective day, Jim Caldwell might even admit it. It’s clear the Lions can’t bring Caldwell back as coach, and if they weren’t sure before, they should be now, after playoff hopes were squashed in a miserable loss at Cincinnati. It’s a harsh truth, and the harsher truth is, firing Caldwell isn’t the full answer, merely the first one. Very soon, the pressure shifts squarely to GM Bob Quinn, who’ll deal with the hangover shortly after the Lions (8-7) close against Green Bay on New Year’s Eve. We’re about to find out if his Patriots pedigree truly is a difference-maker, because this team needs more than just a new coach — it needs a bolder philosophy, a system that isn’t all about winging and hoping with Matthew Stafford. In his second season here, this is Quinn’s chance to officially implement his plan. It was worthwhile to retain Caldwell initially, and a playoff berth bought him another season and a modest one-year extension. Now owner Martha Ford and team president Rod Wood have to further trust the man they entrusted with the franchise’s direction. I believe Quinn was fine keeping Caldwell for two seasons, whether Ford urged him to do so or not, but change is needed now. Quinn has proven to be a solid talent acquirer so far — drafting and free-agent signing — and the Lions have pockets of good players, especially in the secondary and at receiver. Rebuilding the trenches has been a problem, plagued by injuries, but there will be ample opportunity to break down the roster.