Picasso is alleged to have said “Painting is not done to decorate apartments, it is an instrument of war against brutality and darkness.” I suspect that he was referring to his own painting, Guernica, which depicts the horrors of the Spanish Civil War.
I often come across such claims about art—that it has something profound to say about the human condition. But I find them puzzling. What is the point of the commentary of which paintings are capable? How is Guernica an instrument of opposition?
I doubt that anyone learns about the horrors of war from a painting. If you did not already know of the horrors of war you would be unlikely to read the painting as commenting on them. Furthermore, if a gain in knowledge is the point, people who are already acquainted with brutal warfare would receive little benefit from viewing the painting, which seems implausible. And can’t we more effectively learn about historical events from history books or documentaries? Is there some dimension of warfare that is best depicted in paintings? I doubt it.
Perhaps the point is not that we gain knowledge from painting but that paintings are particularly good at provoking an emotional response from the viewer. Perhaps, then, paintings deepen our sensitivity to the horrors of war via their depictions or inspire us to pursue peace. But I doubt that a cool, abstract depiction elicits a more powerful response than actual war footage, filmic representations, live interviews with victims, or reports on the ground by intrepid journalists, all of which seem to pack an emotional punch that paintings rarely if ever achieve. Paintings, because they are fixed entities, lend themselves to contemplation more readily than film. But museums, especially large one’s in major cities visited by hordes of tourists are not conducive to contemplation. (Guernica is housed in Madrid’s Reina Sofia Museum)
Perhaps the viewing of paintings is a reminder that we should care about warfare’s destruction. We clearly need such reminders. But the occasions when such reminders are essential do not correlate well with visits to a museum.
Paintings are valuable, in part, because they give us new ways of organizing and conceptualizing visual space. But that can be accomplished regardless of the content of the painting—such an aim would seem to have little to do with warfare. Paintings—the great ones at any rate—are unique representations of what they depict. But if this is the value of Guernica, it is the uniqueness of its depiction not some fact about the horrors of war that matters most. It is a stretch go call such an aim an instrument in a war against brutality.
So wise and discerning readers. Tell me. What do paintings uniquely say about the human condition? Is Picasso just puffing up his accomplishments.
Exploring the Philosophy of Food and Wine 
There’s a lot here. I’ll respond to a few points.
Early on you seem to question the capacity of art (taken quite generally) to say something profound about the human condition. Your more specific worry is, of course, whether or not painting can do this and, even more particularly, whether it can say something profound about the horrors of war.
First, I think the burden of proof is on you to argue that art, understood very generally, doesn’t provide us with profound insight into the human condition. All of the work done in the humanities, for example, requires mastery of the art and craft of writing. Factual reports about war (the number of dead, the means of killing, who the victims were, et cetera) can say something important about war. Combined with facts about the thoughts and feelings of those involved in war, factual accounts can provide insight into the horror of war. But, reporting the sheer facts alone is unlikely to yield such insight. It is the artful arrangement and presentation of the facts that yields the response. The best historical writing, and the best film documentaries, are great works of art.
Second, assuming that you are really concerned here with the fine arts and their capacity to provide us with deep insight, it seems to me that you are ignoring the fact that when we think about a work of fine art we are engaging actively in a fairly complicated sort of interpretation. We have to learn how to do this, and it isn’t easy. But, once we have acquired the ability to “read” a painting, to understand what a sculpture is “saying”, to grasp the point of a play, then we have access not just to what is unique about the work but also the concepts that the work expresses, its relationship to its tradition, its cultural context, et cetera.
Third, it seems obvious that some novels and some war films (other than documentaries) succeed at providing us with deep insight into the horrors of war (Hemingway’s “For Whom the Bell Tolls”, Mailer’s “The Naked and the Dead”, Kubrick’s “Full Metal Jacket”, Spielberg’s “Saving Private Ryan”, for popular examples), and in a way that outstrips the capacities of more factual works. Stream of consciousness narrative, the capacity to get inside the psychology of multiple characters using other narrative devices, the use of symbolism to create a broader field of relevance, and all of the other many techniques available to the fine artist, broaden the possibilities for conveying insightful truths.
Lastly, taking all of this into account, I see no reason why a painting can’t provide us with insight into the horror of war. Picasso’s “Guernica” clearly says something about war. I think it says something profound, and it depicts horror.
And perhaps an artist can use such a work to assert, in opposition to those who think we ought to go to war, that we shouldn’t. The inferential content (and here I will verge on the simple-minded) might be something like this: War is hell. We ought not generate hell. So, we ought not go to war.