Well, let's consider the opposite side of your question.

Can art be learned?

It's foolish to suggest it can't be, right? Everyone can learn more about art and how to create - how to draw and so on. If art can't be learned what's the point of, say, figure drawing classes? If art can't be learned how do you explain the marked improvement you'll often see when someone participates in such classes?

If art can be learned, then it can be taught. But good artists don't always make good teachers; teaching is its own skillset, of course.

I know a professional artist - my sorta-godmother got me this signed print by her, and I interned for her during some summers where I was volunteering at a local arts center - who couldn't draw, at all, until she was in her mid-thirties or so. She had several friends, and they all wanted to do art, they wanted to be able to draw and sketch and paint and so on, but they weren't very good at it. They all bought copies of Drawing on the Right Side of the Brain, sat down together as a group once or twice a week, and worked their way through the book. At the end of it, they could draw.

I'm not saying my friend-the-artist is doing novel, groundbreaking things with her art. But there's clearly skill there; she can draw a face out of her mind that actually looks like a realistic face. I can draw faces out of my mind that look like...cartoons.

I think innate interest and talent always help one who is pursuing an artistic field, be it music, painting, sculpture, etc - but without a lot of time investment and education, talent will come to naught.