Of one thing I am certain, the body is not the measure of healing, peace is the measure.

The speaker contrasts two yardsticks for “healing”: outward, bodily condition versus inward tranquility. The line suggests that recovery is not fully captured by physical metrics—symptom counts, strength, or appearance—but by the return of a settled mind and spirit. “Peace” functions as an ethical and psychological criterion: one may remain physically impaired yet be healed in the sense of reconciliation, acceptance, and freedom from torment; conversely, a sound body without inner calm can still feel unhealed. The certainty (“Of one thing I am certain”) gives the statement the force of hard-won experience, implying that true convalescence is measured by restored wholeness rather than mere bodily repair.