We analyse the relationship between applicability and effectiveness of legal norms from a philosophical perspective. In particular, we distinguish between two concepts of applicability. The external applicability of norms refers to institutional duties; a norm N is externally applicable if and only if a judge is legally obliged to apply N to some case c. Internal applicability refers instead to the sphere of validity of legal norms. A norm N is internally applicable to actions regulated by its sphere of validity. (...) We also explore the consequences of a thesis which maintains that applicability restricts the concept of effectiveness, so that only applicable norms can be considered effective. Our analysis illustrates that a proper reconstruction of the concept of applicability is of great importance not only for understanding the concept of effectiveness but also for providing insight into the nature of law. (shrink)

Modal interpretations take quantum mechanics as a theory which assigns at all times definite values to magnitudes of quantum systems. In the case of single systems, modal interpretations manage to do so without falling prey to the Kochen and Specker no-go theorem, because they assign values only to a limited set of magnitudes. In this paper I present two further no-go theorems which prove that two modal interpretations become nevertheless problematic when applied to more than one system. The first theorem (...) proves that the modal interpretation proposed by Kochen and by Dieks cannot correlate the values simultaneously assigned to three systems. The second and new theorem proves that the atomic modal interpretation proposed by Bacciagaluppi and Dickson and by Dieks cannot correlate the values simultaneously and sequentially assigned to two systems if one assumes that these correlations are uniquely related to the dynamics of the state of the systems. (shrink)

The modal interpretation of quantum theory ascribes at each instant physical magnitudes with definite values to quantum systems. Starting from certain natural requirements, I determine unique solutions for the evolution of these possessed magnitudes in free systems and in special cases of interacting systems. The evolution is given in terms of transition probabilities that relate the values of the possessed magnitudes at one instant to the values at a second instant. I also determine a joint property ascription to a composite (...) system and its separate subsystems. Finally, I give a proof that the predictions of the modal interpretation with respect to measurement outcomes agree with the predictions of the standard interpretation. (shrink)