  The ontological and epistemological positions adopted by information systems
design methods are incommensur-able when pushed to their extremes. Information
systems research has therefore tended to focus on the similarities between
different positions, usually in search of a single, unifying position. However,
by focusing on the similari-ties, the clarity of argument provided by any one
philoso-phical position is necessarily diminished. Consequently, researchers
often treat the philosophical foundations of design methods as being of only
minor importance. In this paper, we have deliberately chosen to focus on the
differences between various philosophical positions. From this focus, we
believe we can offer a clearer under-standing of the empirical behaviour of
software as viewed from particular philosophical positions. Since the
em-pirical evidence does not favour any single position, we conclude by arguing
for the validity of ad hoc approaches to software design which we believe
provides a stronger and more theoretically grounded approach to software
design.
