Final answer:
Ran Hirschl is the scholar who described the concept of juristocracy, which refers to a system where courts have a strong role in public policy.
Step-by-step explanation:
The scholar who described the concept of juristocracy is Ran Hirschl. Juristocracy refers to a governance system where the judiciary, and in particular high courts, have the ultimate authority to shape public policy and make significant decisions that traditionally fall within the purview of legislative or executive branches. This term is not associated with other individuals mentioned such as Viktor Frankl, a Holocaust survivor and psychiatrist known for his development of logotherapy; Alfred Stepan, a political scientist; or Louis Brandeis, who was indeed a progressive attorney and the first Jewish appointee to the US Supreme Court, known for exposing corruption and defending consumers, but not for coining the term juristocracy.