Information systems often present virtual spaces that are sufficient to enable important human interaction. By enabling such interaction, systems designers are inherently creating certain ethical structures. When one creates an information system, one also creates the ethics for a new world of interaction and such ethics needs specific attention. I outline the basic elements of ethical structures: a framework for interpersonal interaction, personal identity, and structural conditions for customs and rules. I then examine philosophical methods for examining such structures and give a framework for thinking about them in IT systems. Finally, I propose a method to apply ethical design within traditional system development lifecycle models. Applying an ethical framework to IT systems provides more complete conceptual models of systems. Instead of arguing for specific prescriptive rules, I wish to help systems designers understand how they create ethical structures and can do so more with more deliberation.