There is no director alive today who understands the language and history of film better than Martin Scorsese. Whenever he leverages that understanding — in other words, whenever he makes a film — it is usually a treat on some level.

His latest, the period horror thriller “Shutter Island,” seems more like a mature artist’s experiment than a complete work on par with a legacy that includes “Taxi Driver,” “Raging Bull” and at least a half-dozen more of the most essential films of the last 40 years.