In this discussion of Art and Entertainment, someone quoted a professor who suggested that art should entertain, but mostly it should make us think or point us towards change. Entertainment on the other hand does not challenge our deeply held beliefs and tricks us into thinking that we are thinking about something. Here is my reply:
There are some works of art which have not challenged any commonly held belief in me but confirmed them. For example, the Great Gatsby didn't challenge anything I believe about the human desire for perfection and the infinite, but it rendered it in a beautiful and compelling way.
On the other hand, growing up watching the TV show Happy Days, my belief in what it meant to be in "love" or in a relationship was changed. The show constantly presented teenage dating relationships (with physical contact) as cheap, harmless, fun, and morally acceptable. This had an impact on the way I viewed women for the next few years until I realized that my standards were shaped by a TV show rather than the Word. So in this case, something that was clearly not art made me change my beliefs (and I was aware of this change).
So on a practically level, I can't say that I've found your professor's ideas to be reality. Works (like the Great Gatsby) which seem uncontroversially art must by this definition be labeled entertainment, and works (like Happy Days) which seem uncontroversially entertainment must by this definition be labeled art.
On a theoretical level I think these definitions are problematic as well. If art must move someone to change, would a work of art reveling in the majesty of God's creation be entertainment? If the viewer already understood that the world was beautiful and a painting would only reinforce that belief, would it be entertainment? Consider the design of the Israelite Temple. How did the depictions of animals (I believe there were animals...)and fruit change people or bring them to change?
It seems to me that if artists would follow these definitions then they would have to restrict themselves to topics that would produce change, and then art becomes utilitarian and didactic. Much modern art is guided by the philosophy your professor suggested, it is focused on accomplishing a specific end in a person. The result of this idea is that most art now days is political or directed at some social problem, since these topics are the best way to produce tangible change.
And much Christian art is overtly evangelistic, didactic, and shallow because it is focused on "change." So often when we see a work of Christian art it presents itself as a visual alter call. I'm not, of course, suggesting that presenting the Truth of God's Word is wrong in art, far from it! But I am saying that if artists focus too much on changing their audience they are not likely to be able to speak to their audience on an intimate enough level to compel them to change. When artists focus on producing works that cause change it is usually at the expense of properly rendering something about the world. No specific examples come to mind except that old claymation show David and Goliath (which was funny) which was so didactic that the characters seemed inhuman and artificial. Sincerity is almost always the cost of utilitarian art.
So while I think these are interesting definitions that I should probably spend more time considering, I think there are some serious problems them as I understand the definitions.