One of the pervasive phenomena in the history of science is the
development of independent disciplines from the solution or attempted
solutions of problems in other areas of science. In the Twentieth
Century, the creation of specialties witqin the sciences has accelerated
to the point where a large number of scientists in any major branch of
science cannot understand the work of a colleague in another
subdiscipline of his own science. Despite this fragmentation, the
development of techniques or solutions of problems in one area very
often contribute fundamentally to solutions of problems in a seemingly
unrelated field. Therefore, an examination of this phenomenon of the
formation of independent disciplines within the sciences would contrib-
ute to the understanding of their evolution in modern times. We believe
that in this context the history of combinatorial group theory in the
late Nineteenth Century and the Twentieth Century can be used
effectively as a case study. It is a reasonably well-defined independent
specialty, and yet it is closely related to other mathematical
disciplines. The fact that combinatorial group theory has, so far, not
been influenced by the practical needs of science and technology makes
it possible for us to use combinatorial group theory to exhibit the role
of the intellectual aspects of the development of mathematics in a
clearcut manner. There are other features of combinatorial group theory
which appear to make it a reasona- ble choice as the object of a
historical study.