As they gathered near the guarded gates of Columbia University in upper Manhattan on Tuesday, a hundred or so protesters began to chant: “Disclose, divest, we will not stop, we will not rest.” “Divest” is a demand that has been repeated, on banners, in editorials in student newspapers and during rallies that are sweeping across campuses now gripped by a wave of pro-Palestinian activism. What it actually means has varied in scope, and level of detail. At Yale and Cornell, students have called on