The keethara is a Vulcan meditation technique. The approximate translation is "structure of harmony." Building it requires precise balance and spatial acuity. It helps to focus thought and refine mental control. The structure is different each time and dependent on the state of mind of the builder.
The following meditation is 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")