乘剛

At a basic level, the term denotes mounting, riding upon, or occupying a position above something hard, strong, or rigid. In the technical context of the Yi Jing and its commentaries, it describes a structural relationship where a yielding (Yin) line is situated directly above a firm (Yang) line. This interaction typically functions as:

1. Support: The yielding element rests upon the strength of the firm element for stability.

2. Constraint: The yielding element is restricted or pressured by the rigidity of the line beneath it.

3. Utilization: The yielding element avails itself of the firm element's strength to achieve an objective.

Verb-Object construction: 乘 (verb: to ride, ascend, occupy, or avail oneself of) and 剛 (object: the firm or strong quality/element).

The direct structural opposite is 乘柔 (chéng róu), where a firm line sits atop a yielding one.

Avoid rendering 乘 as a literal physical action (e.g., "mounting") if the context implies a systemic arrangement. The term often describes a structural state—a condition of being—rather than a deliberate act. The translator should determine from the surrounding text whether the relationship is one of opportunistic use or inherent structural dependency.