Today something is becoming very clear: the famous triad of viable, feasible and desirable is more than meets the eye.

Sometimes the three elements are given as general success factors: if an offering is viable (supports the success strategy of the organization), feasible (can be developed and maintained within reasonable constraints) and desirable (valued by people enough to be adopted), it will succeed. Sometimes they are three overlapping domains of responsibility, with viability being the primary responsibility of some role representing business, feasibility represented by some engineering discipline and desirability being the responsibility of design.

But each represents a distinct praxis — a mode of thinking and acting. Each situates itself in a different topological relation. Far, near, inside.

Viability is instrumental and strategic reasoning, which aggregates, generalizes, predicts, projects, promises and plans, extending its chains of in-order-to at grand scale. Viability looks out from great heights and surveys immensities of space, time, resources and behaviors, in order to act upon them from a distance. Viability lives from the top floor.

Feasibility is technical praxis. Feasibility gets closer to things, goes hands-on defining, shaping, constructing, manipulating systems, building large objects from smaller components. In feasibility, we work in an objective world, upon objects, as an object among objects. A person is a behaving object, that behaves one way under Condition A and another way under Condition B. Feasibility lives in the middle floors, and provides the concrete structures that lift the top story to its great height.

Desirability is intersubjective praxis. Desirability, however, goes inside, and looks at nested wholes from inside, within the experiences of living subjects. Desirability goes where people are, stands with them where they stand, and looks out with them at their world, from where they are subjectively situated. We are making something to offer them. How will this offering be received in this world we are being shown? Desirability walks about among the people in the strangeness of reality as lived and experienced from myriad centers of the universe. Desirability moves about on the rough ground.

Design must know and respect viability, feasibility and desirability. All three are indispensable.

But design is rooted in desirability and its primary responsibility is desirability.

If design is uprooted from desirability and its responsibilities transferred elsewhere, the work it does might be important and have enormous impact, but that work is no longer design work.

Of course, truth constructors can redefine design in ways that deemphasize its duty to desirability, but not without palpable loss of meaning.