A typical modern paradox emerges from these results. By restricting his cognitive powers to a field of experience in which the concept of force as an objective reality was unthinkable, man has been led on a line of practical investigation the pursuit of which was bound to land him amongst the force-activities of the cosmos. For what distinguishes electric and sub-electric activities from all other forces of physical nature so far known to science, is that for their operation they have no need of the resistance offered by space-bound material bodies; they represent a world of pure dynamics into which spatial limitations do not enter.