Despite rapid and robust advances in "omics", precision therapeutics, bioengineering, and large-scale systems analysis, curing serious disease has remained elusive, suggesting that important limiting factors in therapeutic science may remain insufficiently recognized or understood. This manuscript presents a Socratic dialogue between Philosophos, a seeker of truth, and Hippocrates, the voice of conventional medical wisdom, as they explore the foundations of cancer therapy. The dialogue examines why so many therapies—despite conceptual and engineering elegance—fail in practice. Ineluctably, the exchange converges on a single unifying principle that delivers therapeutic impact precisely, and is the fundamental barrier to progress. The interlocutors agree that achieving the ultimate end of this "holy grail" will unlock the full potential of both existing and future therapies across oncology and many other diseases. More broadly, the dialogue serves as a case study in how scientific fields may overlook fundamental rate-limiting constraints, and how disciplined questioning can reveal the assumptions that shape prevailing research paradigms and guide the next stages of inquiry.