حاول معرفة السبب, و توصل بنفسه إلى نتيجة, أن الطلاب الذين لم يستطيعوا حل مشاكل مثل إصلاح السيارات, لم يكونوا يعملوا بأيديهم.
And he tried to figure out why. And he came to the conclusion, quite on his own, that the students who could no longer solve problems, such as fixing cars, hadn't worked with their hands.