. >> we want to welcome heidi lee feldman, a professor at a georgetown university's law center specializing in what areas? >> legal theory, legal philosophy, basic elements in american law, and some tort law and a completely different world from what we're talking about today. >> well, today, we want to talk about the 25th amendment, section 4, which reads as follows. whenever the vice president and a majority of either the principal officers of the executive departments or of other such bodies as congress may, by law, provide transmit to the president protem of the senate and to the speaker of the house of representatives their written declaration that the president is unable to discharge the powers and duties of his office, the vice president shall immediately assume the powers and duties of the office as acting president. explain why that was put in the constitution. >> so, originally, when the constitution was written in article ii, there is some provision made that's the article of the constitution that sets up the presidency. there's some provision made for what happened -- >> delayed