"This doctrine of interference of undulations was the absolutely novel part of Young's theory. The all compassing genius of Robert Hooke had... very nearly apprehended it more than a century before, as Young himself points out, but... even with the sagacious Hooke it was only a happy guess... and utterly ignored by all others. Young did not know of Hooke's guess until he himself had fully formulated the theory, but he hastened then to give his predecessor all the credit that could possibly be adjudged his due... To Hooke's contemporary, Huyghens, who was the originator of the general doctrine of undulation as the explanation of light, Young renders full justice also. For himself he claims only the merit of having demonstrated the theory which these and a few others of his predecessors had advocated without full proof."