The heading "Mental Conviviality" covers the domain of mental phenomena considered as tools or artefacts. It treats of ideas, conceptual schemes and language systems from the point of view whereby they can be regarded as "tools."

Illich, like others before him, noted that ideas, conceptual schemes and language systems can be regarded as "tools", in that they are human constructs which individuals put to use to achieve specific ends. Under this heading will first be presented examples of this point of view.

Mental Conviviality also covers the analysis of mental tools and how the function, offering reflections on how the individual’s mental apparatus might better serve the goals of that individual. This heading will therefore reviews approaches to what might be called the "design" of mental tools.

Note that the heading "Mental Conviviality" covers the more theoretical aspects of the use of mental tools, while the heading "Personal Convivialty" covers the more practical aspects. Thus the theory of how people use conceptual schemes to guide their individual decisions is covered under "Mental Conviviality," while the practical assimilation by individuals of conceptual schemes from how-to books and web sites is covered under "Personal Conviviality."