In a disordered mind, as in a disordered body, soundness of health is impossible.

Cicero draws an analogy between mental and physical disorder to argue that “health” is an integrated condition: just as bodily illness prevents physical soundness, a mind thrown into confusion by vice, passion, or irrationality cannot be truly well. The remark reflects a broadly Stoic and Platonic moral psychology that Cicero often adopts in his philosophical works, where the state of the soul determines the quality of one’s life. The line implies that ethical and intellectual discipline are not ornamental but therapeutic: order in thought and character is a prerequisite for genuine well-being.