The **core principle** discussed in the "Introduction to Structural Thinking" is that **the underlying structure of anything will determine its behavior**. This is presented as one of the most profound and major points of the course.

This principle stands in contrast to common approaches to problem-solving and change:

*   **Situational vs. Structural Thinking**: Most people tend to think *situationally*, focusing on problems, rather than structurally. For instance, companies often pride themselves on being "dedicated problem solvers." However, structural thinking asserts that you can eliminate all problems and still not achieve your desired outcomes because **"problem solving is not creating, creating is not problem solving"**.
*   **Rejection of Change Efforts**: The sources highlight that many change efforts, even well-intentioned and effective ones (like the quality movement inspired by Deming), are often rejected by organizations over time, much like a body rejects an implanted organ. This occurs because **if the underlying structure is not conducive to change, the organization will reject it, regardless of the quality of the change effort itself**. Conversely, a **change of underlying structure almost invariably leads to a change of behavior**. The common Western tendency is to ask "how do we change it?" before first understanding "how do we understand what's giving rise to the predictable patterns of behavior that we're seeing?".

The underlying structure produces two distinct patterns of behavior:

1.  **Oscillation**: In this pattern, individuals or organizations set out for a particular goal, may achieve it for a period, but then a reversal occurs, and they end up without what they initially sought. Examples include industries that build up capacity and then downsize, centralize and decentralize decisions, or engage in acquisition sprees followed by divestment. While oscillation can be suitable in certain contexts (like a rocking chair), it is considered a **terrible structure for personal life or for a company**. This structural dynamic explains why consultants might do their "best work" in a company, only to find two years later that "it's as if it never happened" – not due to personal failure, but because it wasn't an adequate change of the underlying structure.
2.  **Resolving Advancing Structure**: This pattern leads to an outcome-oriented approach. Instead of being a problem-driven company, an organization shifts to thinking about desired outcomes. This involves clearly defining what is wanted, understanding the current state in relation to that desired outcome, and then determining the best way to move from the current state to the desired state. This process requires clarity on both the desired outcome and the current reality, and an iterative learning process to adapt as reality changes.

The fundamental dynamic underpinning structural thinking is that **structure seeks equilibrium**. This drive for equilibrium is the causal force behind events. **Tension**, in this context, is not stress or anxiety, but rather a **"structure of a contrast between a desired state and an actual state"**. This difference creates a state of non-equilibrium, which then naturally seeks equilibrium. In a proper creative process, the current state is brought up to the level of the desired state, achieving a state of equality or equilibrium.