The keethara was a Vulcan meditation technique. The approximate translation was "structure of harmony." Building it required precise balance and spatial acuity. It helped to focus thought and refine mental control. The structure was different each time and dependent on the state of mind of the builder.
The following meditation was recited: "Structure. Logic. Function. Control. The structure cannot stand without a foundation. Logic is the foundation of function. Function is the essence of control. I am in control. I am in control." (VOY: "Flashback")