Roger Ebert gave this review:
Bernardo Bertolucci's "Last Tango in Paris" is one of the great emotional experiences of our time. It's a movie that exists so resolutely on the level of emotion, indeed, that possibly only Marlon Brando, of all living actors, could have played its lead. Who else can act so brutally and imply such vulnerability and need?
For the movie is about need; about the terrible hunger that its hero, Paul, feels for the touch of another human heart. He is a man whose whole existence has been reduced to a cry for help -- and who has been so damaged by life that he can only express that cry in acts of crude sexuality.
I've never seen it, but I've heard some good things about it. Hope this helps.