He found that they were resistant to deducing the hypothetical, to speculating about what might be, and he found finally that they didn't deal well with abstractions or using logic on those abstractions.
Va esbrinar que es resistien a deduir des de la hipòtesis, a especular sobre què hagués pogut ésser, i va descobrir, finalment, que no s'enfrontaven bé a les abstaccions, o a l'ús de la lògica en aquestes abstraccions.