What is this thing called theory, and what does it do? James Corner has highlighted the contrast between two fundamentally different roles of theory. On the one hand, theory can generalize and codify knowledge, as a basis for practical action. This corresponds to the type of theory described by Garrett Eckbo in “Landscape for Living”, as “the generalization of social experience”. Such instrumental theory is typically derived from empirical observation. For example, Joan lverson Nassauer’s development of the concept of “cues for care” as a means to “frame” ecological restoration projects in a culturally acceptable way was developed from surveys of the attitudes of Midwestern farmers. Theory can also evolve from practical experience. The staged approach to site planning, codified into a set of principles by Kevin Lynch and John Ormsbee Simonds, is one of the most widely used theories in landscape architecture. It illustrates the way that such theory can provide a stable and coherent framework for a discipline.
On the other hand, theory can have a more critical role, which resists and challenges taken-for-granted ways of thinking, and puts forward alternatives. Elizabeth Meyer’s exploration of landscape architecture as other is an example of a critical theory. It challenges the modern view of landscape as a largely passive setting (or ground) for architecture, and instead argues for landscape architecture as an autonomous design practice expressing its own language of space and form. A second example of a critical theory is Corner’s advocacy of “recovering” landscape, with a consequential recasting of its role from being a passive product of culture to become an active and strategic agent of culture. Theoretical work that critiques current knowledge in this way disrupts and destabilizes the discipline, stimulating a search for new forms of knowledge and new ways of working.
Another potential role for theory lies between these two positions. Corner referred to the hermeneutic tradition of interpretation, and interpretive theory is well recognized in related disciplines as a form of knowledge that does not attempt to predict and control the world in the same way as instrumental theory, yet neither is it as disruptive as critical theory. Instead, an interpretive theory helps us better understand a situation, without necessarily changing it. Much of the knowledge of landscape history expressed in J. B. Jackson’s work is interpretive in this sense.
Michael Heizer, Double Negative (1970)