text: Federal law allows patents on a very broad range of new inventions, but there are a few exceptions. Laws of nature, physical phenomena and abstract ideas aren’t patentable. The issue in the case is whether the Prometheus patents run afoul of these prohibitions. The Supreme Court at times appeared to struggle with how to distinguish patents on laws of nature, which are prohibited, from patents that apply the laws of nature, which are allowable.
  “Doesn’t any medical patent rely on natural processes?” Justice Antonin Scalia asked. “I mean, even if you invent a new drug, what that new drug does is natural. It affects the human physiognomy in a certain natural way.”
  Justice Stephen Breyer expressed concern about the patents, but he also noted the investments that companies have made. “Discovering natural laws is often a very expensive process,” he said.
  In a 2006 dissenting opinion, Breyer questioned the validity of some medical diagnostic-test patents, but he said Wednesday that his earlier opinion didn’t answer certain tough questions.