Is Sidgwick's Dualism really a middle ground between Ethical Egoism and Utilitarianism?

What will be an ideal response?

Some would argue that Ethical Egoism and Utilitarianism are at two extreme ends of a continuum to be reconciled with any other framework. One argument is that Ethical Egoism is so self centered that it is only by luck that it would also support utilitarianism approach. Alternatively, supporters of Ethical Egoism would state that there has to be some type of self interest in all decisions even though they are presented as providing the greatest good for the greatest number. Sidgwick argues that there can be a common ground by examining the rational benevolence perspective of the utilitarianism approach and the prudence perspective of the ethical egoism approach. Adam Smith would be a good example of how the "invisible hand" guides financial and society based decisions. His argument is that there is an opportunity to focus on both the self interests of the decision maker and what is best for society. However, an underlying assumption of Smith's argument is that society and individuals will have the same goals and objectives. If this assumption is true, then financial decisions by individuals will help guide societal decisions, which will produce actions that provide the greatest good for the greatest number.