Through a comparison of the historical perspectives of medieval and modern libraries, this paper is designed to clarify the purpose and goals of the library, and to promote a public and intellectual debate to guide future developments. The Middle Ages were chosen because libraries possessed an importance and centrality to learning, civilization, and intellectual debate that has not been duplicated since that time. The modern academic library was chosen as the basis of comparison because it corresponds the most closely with the medieval library in terms of overall intellectual trends. An examination of the institutional and social contexts of libraries in both time periods includes discussions of preservation, scholasticism, size and scope of collections, and the library's role. A discussion of the library service concept and its role in helping to decide some of the academic institution's goals concludes the paper. A 17-item bibliography is provided. (THC)