Only if one had somehow shown that gravity and electricity were not original special forces of nature, but only the manifestations of a more general force already known, would it be allowable to ask for the cause which made this force produce the phenomena of gravity or of electricity here.
Bakarrik, agertu izan balitz pisutasuna, elektrizitatea ez natur indar jatorrizko, propioak, baizik natur indar jadanik ezagunago, orokorrago baten agerpen-erak bakarrik direla, orduan galde liteke kausaz, zeinak egiten baitu natur indar horiek hemen pisutasunaren, elektrizitatearen agerpena sorraraztea.