From a philosophical point of view, Leibniz's most interesting argument was that absolute space conflicted with what he called the principle of the identity of indiscernibles (PII). PII says that if two objects are indiscernible, then they are identical, i.e. they are really one and the same object. What does it mean to call two objects indiscernible? It means that no difference at all can be found between them--they have exactly the same attributes. So if PII is true, then any two genuinely distinct objects must differ in at least one of their attributes--otherwise they would be one, not two. PII is intuitively quite compelling. It certainly is not easy to find an example of two distinct objects that share all their attributes. Even two mass-produced factory goods will normally differ in innumerable ways, even if the differences cannot be detected with the naked eye.Leibniz asks us to imagine two different universes, both containing exactly the same objects. In Universe One, each object occupies a particular location in absolute space.In Universe Two, each object has been shifted to a different location in absolute space, two miles to the east (for example). There would be no way of telling these two universes apart. For we cannot observe the position of an object in absolute space, as Newton himself admitted. All we can observe are the positions of objects relative to each other, and these would remain unchanged--for all objects are shifted by the same amount. No observations or experiments could ever reveal whether we lived in universe One or Two.
The century of Einstein and Planck was also the century of Hitler. The Gestapo and the scientific renaissance were children of the same age. How humane the nineteenth century seemed, that century of naive physics, when compared with the twentieth century, the century that had killed his [Viktor's] mother. There is a terrible similarity between the principles of Fascism and those of contemporary physics.Fascism has rejected the concept of a separate individuality, the concept of "a man," and operates only with vast aggregates. Contemporary physics speaks of the greater or lesser probability of occurrences within this or that aggregate of individual particles. And are not the terrible mechanics of Fascism founded on the principle of quantum politics, of political probability?Fascism arrived at the idea of the liquidation of entire strata of the population, of entire nations and races, on the grounds that there was a greater probability of overt or covert opposition among these groupings than among others: the mechanics of probabilities and of human aggregates.But no! No! And again no! Fascism will perish for the very reason that it has applied to man the laws applicable to atoms and cobblestones!Man and Fascism cannot co-exist. If Fascism conquers, man will cease to exist and there will remain only man-like creatures that have undergone an internal transformation. But if man, man who is endowed with reason and kindness, should conquer, then Fascism must perish, and those who have submitted to it will once again become people.