As the organisers hoped, the systems thinking and theory sessions saw the exploration of almost all the important avenues of current systems research. Different speakers focussed on cybernetics, systems engineering, systems dynamics, soft systems thinking, operational research, general systems theory and critical systems thinking, and sought to chart likely developments over the next ten years in their areas of expertise. Fortunately, though, this necessary specialisation did not lead to a fragmentation of debate. More than at any other systems conference the editors have attended there was a willingness to discuss the interrelationships between the different strands of the systems movement. Perhaps this openness was one of the main achievements of the conference and it was a hopeful pointer for the next ten years. For the proper theorising of the relationship between the tendencies that make up the systems movement is certainly one of the most important challenges that the systems community faces in the decade to come. Its future growth and prosperity as a unified body of scholars and practitioners, and the realisation of its potential for massively increased influence in the affairs of organisations and societies, crucially depend upon the resolution of this problem.