An analogy used by Maitreya Bodhisattva in the Uttaratantra Shastra aptly defines the Four Noble Truths. When treating any illness, doctors need to take four steps: 1) to ascertain the nature of the illness; 2) to eliminate the cause of the illness, since it would be ineffective to treat only the symptoms; 3) to prescribe remedies; 4) to heal. All doctors must go through this four-step process to treat an illness. Not knowing the cause of the illness, the doctor cannot prescribe a cure. Even knowing the cause of the illness but having no suitable medicine or the requisite pharmacological knowledge, or worse, giving the wrong prescription, the doctor will still be rendered ineffective. Nevertheless, everything that is concerned with treating a patient starts with identifying the cause of the illness. The Four Noble Truths also correspond to the four steps of treating an illness. The nature of suffering is what to be ascertained, the origin of suffering to be eliminated; the path leading to the cessation of suffering is what to be practiced (prescription), the cessation of suffering to be attained (cure).
[Depicted from The Right View - The Four Noble Truths"]