Forcing yourself to use restricted means is the sort of restraint that liberates invention. It obliges you to make a kind of progress that you can't even imagine in advance.
Pablo PicassoPhotography has arrived at the point where it is capable of liberating painting from all literature, from the anecdote, and even from the subject. In any case, a certain aspect of the subject now belongs to the domain of photography. So shouldn't painters profit from their newly acquired liberty, and make use of it to do other things?
Pablo PicassoFor being a bad student I was banished to the 'calaboose' - a bare cell with whitewashed walls and a bench to sit on. I liked it there, because I took along a sketch pad and drew incessantly I could have stayed there forever drawing without stopping
Pablo Picasso