In the Masnavi, Rumi uses the story of the ancient physician Galen fearing a madman's flattery to explain the spiritual law of affinity or homogeneity (jinsiyyah). When a madman smiles, winks, and tears Galen's sleeve, Galen immediately requests medicine for madness from his disciples. When his companions object that Galen is the peak of intellect, Galen explains that the madman would not have approached him unless he perceived some common element (qadr-e moshtarak) or shared trait between them. Rumi employs this narrative to demonstrate that outer attraction reflects inner correspondence, warning that keeping company with those of a different spiritual nature is spiritually suffocating.