Even at a dinner or a card-table, each of them had to be certain that, in the diner or partner who sat opposite to him, there was, latent and not yet made use of, a certain brand of knowledge which would enable him to identify the rubbish with which so many houses in Paris were littered as genuine medieval or renaissance “pieces” and, whatever the subject of discussion, to apply the critical standards common to all their party whereby they distinguished good work from bad. Probably it was only⁠—at such moments⁠—by some infrequent, amusing interruption flung into the general silence of meal or game, or by the new and charming frock which the young actress had put on for luncheon or for poker, that the special kind of existence in which these four friends desired, above all things, to remain plunged was made apparent. But by engulfing them thus in a system of habits which they knew by heart it sufficed to protect them from the mystery of the life that was going on all round them.