Where does one draw the line in art?
I have read your answers to the questions concerning art, films, and novels. You said that viewing/reading imperfect and certain morally problematic works are not necessarily sinful, unless it's an occasion of sin for a particular person.
The Catechism of the Catholic Church defines pornography:
Pornography consists in removing real or simulated sexual acts from the intimacy of the partners, in order to display them deliberately to third parties (CCC 2354).
Fr. Francis Ripley in his book written for laypeople, This Is the Faith, states:
The Sixth Commandment also forbids immodest songs, books, pictures, movies, TV shows, and websites....
He also states that reading obscene books is a mortal sin, and reading unsavory newspaper articles is sinful.
Given the definition of pornography, most films, including The Mission, Schindler's List, and Masterpiece Theatre, are gravely sinful to watch due to their sexual content alone. If immodest/suggestive artworks are forbidden, most artworks are forbidden, even "Catholic classics" such as Brideshead Revisited. What do you think? Is Fr. Ripley correct? Are most artworks therefore sinful to create and enjoy? Where does one draw the line between sin and art? What about sin as a subject in art?
Since the Vatican, which authorized the Catechism of the Catholic Church, included both The Mission and Schindler's List in its compilation of 45 of the "best films" (source), I think we have to conclude that you might have misunderstood the Church's definition of pornography and perhaps also Fr. Ripley's understanding of "modesty." Here is the Catechism's definition of "modesty":
Modesty protects the mystery of persons and their love. It encourages patience and moderation in loving relationships; it requires that the conditions for the definitive giving and commitment of man and woman to one another be fulfilled. Modesty is decency. It inspires one's choice of clothing. It keeps silence or reserve where there is evident risk of unhealthy curiosity. It is discreet (CCC 2522).
You have also left off an important part of the Catechism's treatment of pornography. It goes on to state:
... It offends against chastity because it perverts the conjugal act, the intimate giving of spouses to each other. It does grave injury to the dignity of its participants (actors, vendors, the public), since each one becomes an object of base pleasure and illicit profit for others. It immerses all who are involved in the illusion of a fantasy world. It is a grave offense. Civil authorities should prevent the production and distribution of pornographic materials (CCC 2354, emphasis added).
The emphases indicate where the Church is defining what it means by "pornography." Pornography "perverts the conjugal act," it objectifies and makes illicit profit off of persons, it creates an illegitimate illusory fantasy world. Art, films, and novels that don't do this therefore do not qualify as "pornography," by this definition.
As for modesty, the Catechism's treatment of it illustrates that it is about more than the amount of skin shown or the parts of the body discussed or represented. It's a virtue that protects the dignity of human persons and their love for each other. Choice of clothing and patterns of speech contribute to attaining that virtue, but they do not inherently define it.