Pinel states that Jean-Baptiste Pussin often defined the psychological approach to be used, because "he lived amongst the insane night and day, studied their ways, their character, and their tastes, the course of their derangements, knows when to be benevolent, when to be an imposing figure...", allowing him to know the individuals more than a physician could by making his rounds.
Pinel udtaler, at Jean-Baptiste Pussin ofte fastlagde den psykologiske tilgang, der skulle bruges, fordi "han boede blandt de vanvittige nat og dag, studerede deres måder, deres karakter og deres smag, i løbet af deres derangement, ved, hvornår at være godgørende, og at være en imponerende person ... ", hvilket fik ham til at kende de personer bedre end en læge kunne ved at gøre sine runder.