Two lectures on small x and high gluon density

In these lectures, I shall discuss small x physics and the consequences of the high gluon density which arises as x decreases. I argue that an underst anding of this problem would lead to knowledge of the high energy asymptoti cs of hadronic processes. The high gluon density should allow a first princ iples computation of these asymptotics from QCD. This physics might be expe rimentally probed in heavy ion colliders or in high energy electron-nuclear collisions.