"When the flush of a new-born sun fell first on Eden's geen and gold,
Our father Adam sat under the Tree and scratched with a stick in the mould;
And the first rude sketch that the world had seen was joy to his mighty heart,
Till the Devil whispered behind the leaves, 'It's pretty, but is it Art?'"
-- Rudyard Kipling, the Conundrum of the Workshops
I really do believe that the argument about "what is art" started at this point in time. I remember when my mother saw her first Jackson Pollock painting, she said "That's awful! It looks like a 3-year-old did it." Then, later, she decided that modern art was cool and hung a Picasso print over the piano. When I has in high school my best friend's mother had the same one in their house.
Go to http://www.jacksonpollock.org/ and you can practice painting just like he did! Just move your cursor around and click to change colors.