The idea of this symposium grew out of our discussions on the need to review the advances that had been made in the theoretical description of inelastic scattering reactions in the last few years. Since a microscopic description of inelastic scattering uses realistic effective interactions, we felt that it was appropriate to begin such a summary with a discussion of the free two-nucleon force. However as we thought further about this review, it became increasingly apparent that a rather more ambitious program linking the free two-nucleon force and nuclear matter calculations both to shell model calculations and to reaction theory, would be appropriate and perhaps even necessary to do full justice to the subject. We hope that the symposium as it emerged did fulfill these aims, better perhaps than we expected. There are some comments required concerning the presentation of the material. First the papers are grouped by session number for convenient gathering of the same topic in the same place. Secondly, because of the rather tight constraint on pages, it was possible to print only those contributions which were presented orally at the symposium. The remainner are included as abstracts. The full text of all the contributed papers is available as a Michigan State University Cyclotron Laboratory Report (MSUCL 39/1971).