What if, for some one of the subtler reasons that would tell with both of them, they should tire of each other, misunderstand or irritate each other?
He had dawdled over his cigar because he was at heart a dilettante, and thinking over a pleasure to come often gave him a subtler satisfaction than its realisation.
Only old Catherine Mingott, with her absence of moral prejudices and almost parvenu indifference to the subtler distinctions, might have bridged the abyss; but she had never opened a book or looked at a picture, and cared for music only because it reminded her of gala nights at the Italiens, in the days of her triumph at the Tuileries.
He had been before in drawing-rooms hung with red damask, with pictures "of the Italian school"; what struck him was the way in which Medora Manson’s shabby hired house, with its blighted background of pampas grass and Rogers statuettes, had, by a turn of the hand, and the skilful use of a few properties, been transformed into something intimate, "foreign," subtly suggestive of old romantic scenes and sentiments.
not obvious, but understandable by someone with adequate sensitivity and relevant knowledge (perhaps depending upon fine distinctions)
capable of understanding things that require sensitivity and relevant knowledge (perhaps understanding fine distinctions)