ABSTRACT
The great leitmotiv of the Middle Ages was universalia sunt realia. But the finale of the Middle Ages was summed up in the sentence: there are no universalia. Positivism takes its last refuge in the consolation that all these differences in strain, potential differences, functions, paths, velocities, lines of force, and other symbols of embarrassment can be expressed by exact mathematical equations. Conceptions of 'before' and 'after', which have meaning only in relation to a given station in time, are the same as space-conceptions of 'over' and 'under', which depend purely on the place of the observer. The assertion that two events are simultaneous, then, has only meaning if it is made in relation to a definite system of motion. Horbiger's conception differs from previous ones on several essential points, primarily in the infinitely bigger role given to ice as constructive material, but above all because of its dynamic form.
