Why do we need a robust theory of activities?

So far, everyday mundane activities do not have a theory. Although, such theory can be helpful in many ways. A preliminary theory of activities will divide them into ‘useful’ and ‘harmful or useless’. We can develop interventions to promote useful activities. A simple four-step pathway of disease causation and disease regression has been envisaged. Activities occupy very important place in this pathway. Interventions leading to large scale positive changes in activities will improve the quality of healthcare by reducing its need. Such large-scale positive changes in activities may become a vehicle for development of better-quality individuals and a better society.