When we did Gouraud shading didn't we interpolate illumination values that we found at each vertex using screen-space interpolation?

Didn't I just say that screen-space interpolation is wrong (I believe "inherently flawed" were my exact words)?

Does that mean that Gouraud shading is wrong?

Is everything that I've been telling you all one big lie?

Has 6.837 amounted to a total waste of time?