The article attempts to think through the original purpose of the Fifth Amendment and argues for an interpretation that emphasizes the notion of compulsion rather than the issue of self-incrimination.
The most important historical point that the authors make is that the Fifth Amendment was written in a period in which many countries used torture to elicit confessions. Even more importantly, much of European law was based on Roman Law, in which the testimony of slaves was considered invalid unless they were tortured. The authors thus suggest that we should read the word "compelled" as a key to understanding the purpose of the amendment. The point they make is that it was designed to prevent any form of compulsion. This is especially relevant in cases where confessions may, even now, be elicited by threats or other marginally unethical interrogation techniques, or even by police brutality.
The authors also argue that part of how we should think about the Fifth Amendment is in terms of the balance between actual evidence and testimony. They suggest that part of how we analyze the Fifth Amendment should emphasize that testimony is less reliable than other forms of evidence, such as physical evidence and paper trails.
Finally, the authors suggest that the Fifth Amendment should not be used to prevent defendants from testifying on their own behalf or providing testimony in general, but only that there should be no element of compulsion.