In the previous three parts of our investigation into the problem of inter subjectivity, an attempt has been made to lay out Mead, Gurwitsch, and Schutz's theory of intersubjectivity, and to draw out some of the limitations of each. Our analyses of these theories were held, for the most part, somewhat separate from one another in order to clearly present and criticize the relevant author's theory of intersubjectivity which was usually quite implicit in his own work and quite complex in itself. In general, the intention was not to make an already very difficult subject matter even more difficult by entering into comparisons at such an early stage of our analyses. In the present chapter, it is precisely such comparisons which will be provided. However, the main goal of this chapter is not merely to provide comparisons, although those which are presented are hoped to be quite illuminating.