Concealed by this summary is Decoud voicing his idea of Separation, which they
are already discussing when the dialogue returns a moment later. Also "half
hid" is Decoud's capitulation to Antonia, and his acceptance of idealism.
He begins by wanting to "carry her away" on the basis of his skepticism
(ideals are "deadly futilities"), but she refuses (Decoud relates as
much to Mrs Gould later). To him all dream-ideals are "wrong -- utterly wrong,"
but as she continues, he feels an "unwilling thrill of interest" in
the ideals of Costaguana politics. His vivid image of the schoolgirl Antonia emphasizes
that this is a struggle at the root -- his intellectual skepticism vs. all the
desirability of idealism that she embodies. Observe that he admires the "genius
" of her passion as opposed to intellect: i.e., it occurs to him that
illusion is a wiser response to the world than the barren, fatal truth of skepticism.
Finally he is "seduced" by her -- his "murmur of assent" is
still made against his will, but by the time they begin to argue they are already
discussing Separation: he has entered "quite seriously" into her world.