Kaplan’s canonical contribution is to define restoration not as passive relaxation but as the recovery of a finite cognitive capacity: directed attention. Attention Restoration Theory treats sustained voluntary focus as an effortful inhibitory operation that becomes fatigued under prolonged demand, while certain environments permit recovery because they solicit attention without requiring coercive concentration. Nature is especially effective because it commonly combines being away, extent, fascination and compatibility, producing a mode of perceptual engagement that is absorbing without being exhausting. The theoretical importance of the paper lies in its attempt to reconcile attentional restoration with stress-reduction approaches rather than collapsing one into the other. Its conceptual operation is therefore integrative: psychological fatigue, environmental affordance and restorative experience are placed within a larger human–environment system. The bridge to environmental design is precise: spatial form can be evaluated not only by use, beauty or symbolism, but by the kinds of attentional economies it sustains.
