What is the contribution of painting in art history?

I agree. I took AP Art History and the idea of paintings and other art forms are to record history and reflect the artist's thoughts on a particular subject much like an author does with writing. Paintings are a contribution in telling one about society and the mindset of the artist. Take for example the highly technical paintings of the Renaissance. Those artist were embracing the new ideas of individualism which led to the study of the human and thus fields of in science and more. The highly detailed art shows the change in society.

I hope this makes sense :)