In this paper I have described some of Rosenfeld's ideas about narcissism, and in particular the distinction he makes between libidinal and destructive narcissism. Using a clinical example to illustrate the struggle between dependency and the power of excitement and destruction, I have attempted to show some narcissistic defences in action. I have argued that while Rosenfeld's differentiation may not hold, in that both constructive and destructive elements are always present, he has identified vividly important elements. The degree of the destructiveness, the extent to which it is split-off, hidden and unavailable, the extent to which it is maintained by excitement and eroticisation, and the rigidity of the organisation that has been set up (that is, where or not much is allowed in from outside) are all crucial. What needs to be distinguished are states of mind, and which state of mind is in the ascendancy at any one time. I have reviewed briefly some of the theories advanced to explain why these defences come into existence, and I have mentioned some of the consequent implications for technique.