Giddens distinguishes between structure and system, and asserts “the duality of structure.” He writes: “by the duality of structure I mean that social structure is both constituted by human agency and yet is at the same time the very medium of this constitution” (New Rules).
Structure and agency form a duality, which Giddens distinguishes from a dualism. He regards the two aspects of a duality as correlated and interdependent with neither aspect as equivalent nor reducible to the other. In contrast, aspects of a dualism necessarily oppose or exclude each other.
The concept of the duality of structure rejects the perception that structure is some steel cage that encloses agents who are interacting within the cage, have been interacting before being in the cage, and can interact outside it. For Giddens, structure enters into the very constitution of action and interaction. Structure is both a medium and an outcome of agency, and thus, “structure must not be conceptualized as simply placing constraints upon human agency, but as enabling” (New Rules). Structural constraint and empowerment also form a duality.
The constraint-empowerment duality is illustrated well by the process of learning a language. Giddens says:
“Since any language constrains thought (and action) in the sense that it presumes a range of framed, rule-governed properties, the process of language learning sets certain limits to cognition and activity. But by the very same token the learning of a language greatly expands the cognitive and practical capacities of the individual.” (New Rules)
For example, training a child how to communicate verbally, how to substitute words and sentences for its cries and screams, is a form of social pressure. Yet undeniably, such training empowers the child.
For another example of structural constraint cum empowerment, one can refer to the method of scientific practice. The scientific method requires the following of some procedures and the avoidance of other procedures in the pursuit of reliable knowledge. Whether in science or in education, a degree of discipline is required from the participants, and this discipline is both constraining and enabling.
For another illustration, consider the practice of dressing formally. It disposes the wearers and observers to do some gestures or types of behaviour and to avoid others. A structure is comparable to a perspective, which enables one to focus on certain phenomena while inhibiting or blurring the vision of other phenomena. Thus, to say that structure only constrains is like saying that one’s eyes only prevent one from seeing directly the back of one’s head.
The constraint-empowerment duality applies to each and every participant of an interaction. No participant is merely constrained or merely empowered, although in many contexts of interaction, some participants do tend to be more constrained or more empowered than the others.
As conceptualized by Giddens, the duality of structure denies determinism, whether economic, technological, bureaucratic, or cultural. “Determinism…refers to any theoretical scheme which reduces human action solely to event causality,” which Giddens contrasts with “agent causality” (New Rules).
Agent causality and the duality of structure are meant to be interlocked concepts, and thus, both have to be understood neither in a voluntaristic nor a deterministic sense. “The conception of agency in structuration theory resists the polarities of both thoroughgoing determinism and unqualified freedom, while preserving all possibilities between these extremes” (Ira Cohen).
If one wants the common good to be the fruit of structural changes in the economic, political and cultural realms, social reformers have to clarify to themselves what forms of empowerment and constraint would new structures yield and what groups would likely end up more empowered and more constrained in their social interactions.