This chapter investigates the fundamental difference made by Keynes in the General Theory between voluntary unemployment, on the one hand, and involuntary unemployment, on the other. In Keynes, voluntary unemployment is very wide-ranging in that it corresponds to any form of imperfections in wage bargaining, inadequacy in qualifications and so on. In order to understand involuntary unemployment correctly, we have to leave aside the issue of a local reduction in nominal wage: the issue is the effect of a general fall in money-wages on the long-term state of expectations. Significantly, Keynes abandons this terminology after the General Theory and subsequently refers to the distinction between structural unemployment and demand-deficiency unemployment.