In philosophical terms, a key issue of communities of practice (CoPs) can be located within one of the key philosophical debates. The need for CoPs is traceable to the inadequacy in certain contexts of the so-called scientific or problem-solving method, which treats problems as independent of the people engaged on them. Examples of this can be drawn from the management domains of information systems development, project management, planning, and many others. In information systems development, for example, the whole basis of traditional systems analysis and design requires such an approach. In essence, in undertaking problem solving, the world is viewed as though it is made up of hard, tangible objects, which exist independently of human perception and about which knowledge may be accumulated by making the objects themselves the focus of our study. A more human-centered approach would, by contrast, see the world as interpreted through human perceptions: the reason why the problem cannot be solved is precisely because it lacks the objective reality required for problem solving. In taking this perspective, it may or may not be accepted that there exists a real world “out there”, but in any event, the position adopted is that our world can be known only through the perceptions of human participants. This question of objective reality is one with which philosophers have struggled for at least 2,500 years, and an understanding of it is essential to determining the need for, and purpose of, CoPs. The next section therefore discusses some of the philosophical issues relevant to the subjective-objective debate: a search for what, in these terms, it is possible for us to know and how we might know it.