At the beginning of his career, Einstein did not think that Newtonian mechanics was enough to bring together the laws of classical mechanics and the laws of the electromagnetic field. Between 1902–1909 he developed the theory of special relativity to correct that. Einstein also thought that Isaac Newton's idea of gravity was not completely correct. So, he extended his ideas on special relativity to include gravity. In 1916, he published a paper on general relativity with his theory of gravitation.