This is a tough one. He's had a lot of post season success, and he's had some dominant seasons, however his career stats aren't completely convincing. (Not that they aren't good...but they'd have to be good for it to even be a discussion.)
For discussion's sake, here's his career line
216-146, 3,116 Ks, 3.46 career ERA.
Here's his Baseball-Reference page if you want to look at more stats.
Curt Schilling Statistics - Baseball-Reference.com
Yes or No