Human beings are weak creatures.

[He states it plainly, well aware that he himself is also a human.]

They have the potential to be powerful, and certainly are, if their emotions are used productively.

[But they're still weak. That's why he was able to torture so many. None of them could overpower him. None could escape.]

It sounds as if your friend used his emotions for his wife to fuel his productivity in researching something quite advanced.

[Even if he finds it rather silly that a man could grieve so horribly over a dead spouse.]

Oh? And what led you to torture? Was it part of your director's little experiment?