  This article considers the Dissertatio de Arte Combinatoria, published in
1666 and relatively neglected by Leibniz s scholars. However in recent times
the tide seems to be changing. Our work presents three main parts (sections II,
III and IV, respectively). The first one exposes the contributions of M. Serres
and E. Knobloch, viewed from our stand-point. The second one emphazises the
role played by the symmetric group as the underlying mathematical structure of
the Opus. Finally we treat the caput variationis which, in our opinion, is the
fundamental concept of the Dissertatio. Moreover, it is suggested that the
importance of such a theoretical insight may be traced in many aspects of
Leibniz s subsequent thought.
