In the soliloquy, she spurns her feminine characteristics, crying out “uns.ex me here” and wishing that the milk in her breasts would be exchanged for “gall” so that she could m.urder Dun.can herself. These remarks manifest Lady Macbeth's belief that manhood is defined by mu.rder.
I believe that it is purpose. It is not theme nor pathos. I do not think that it is thesis because this paragraph states the thesis of the Deceleration of Independence. Hope this Helps!