Ricardo Silva

The clarification of the relation between norm and value was historically one of the main philosophical concerns of the phenomenological current of the movement known as Philosophy of Values. One of its major characters, Nicolai Hartrnann, in his bookEthik, argues in favor of almost identifying one with the other. For him, the “ideal ought-to-be” (the one indifferent to the way reality is) already belongs to the nature of values, since they have an inherent tendency towards reality. In this communication, I’ll criticize this thesis based on the meaning of the concepts involved.

Começo por distinguir entre proibição em abstrato (tipicidade) e proibição em concreto (ilicitude), situando o estado de necessidade justificante ao nível das causas de exclusão da ilicitude. Relaciono a exclusão da ilicitude resultante do estado de necessidade com a noção de ‘bem’ em sentido integral ou agregado. Depois, passo ao ponto principal deste ensaio, aplicando a teoria da diferença, usada no cálculo da indemnização em sede de responsabilidade civil, para aferir se há ou não superioridade do interesse salvaguardado face ao interesse sacrificado. Por fim, defendo essa aplicação de algumas objeções que podem ser levantadas.

O dilema de Jørgensen tem atormentado os imperativistas até aos nossos dias. Resumidamente, se há uma Lógica das Normas, então esta tem por elementos proposições (as proposições normativas) e, simultaneamente, tem por elementos imperativos, que não possuem conteúdo proposicional. Neste ensaio, defender-se-á que o imperativismo é totalmente compatível com a concebilidade de uma Lógica Deôntica de proposições, pelo que não é necessário afastá-lo para manter a referida concebilidade (ainda que haja outras razões para rejeitar o imperativismo). Todas as posições que aceitam a incompatibilidade suscitada pelo dilema de Jørgensen incorrem num erro, o de confundir imperativismo e prescritivismo. Jørgensen's dilemma has plagued imperativists to this day. Briefly, if there is a Logic of Norms, then propositions participate in it (normative propositions) and, simultaneously, imperatives participate in it, which do not have propositional content. In this essay, I will argue that imperativism is fully compatible with the conceivability of a Deontic Logic of propositions, so it is not necessary to push it aside to maintain that conceivability (although there are other reasons for rejecting imperativism). All positions that accept the incompatibility raised by Jørgensen's dilemma incur an error, that of confusing imperativism and prescriptivism.

Church's Undecidability Theorem is one of the meta-theoretical results of the mid-third decade of the last century, which along with other limiting theorems such as those of Gödel and Tarski have generated endless reflections and analyzes, both within the framework of the formal sciences, that is, mathematics, logic and theoretical computation, as well as outside them, especially the philosophy of mathematics, philosophy of logic and philosophy of mind. We propose, as a general purpose of this article, to formulate Church's Undecidability Theorem and present the main ideas of its demonstration. In order to carry out the first objective, we need to introduce and explain the notions of recursive function and numbering used by Gödel, which will allow to formally and rigorously enunciate Church's Theorem. After we enunciate Church's Theorem of Unspeakability in a formal and rigorous manner, we will present the main ideas of the proof of Church's Undecidability Theorem for First Order Logic, which uses Robinson's axiomatic system for arithmetic and four facts about himself: In Robinson's system for arithmetic recursive functions are representable Robinson's system is undecidable, The number of axioms proper to the Robinson system is finite and The logical calculation of the Robinson system is equal to the calculation of the first-order logic.

The present paper has three objectives: Presenting an actualization of a proof of the decidability of monadic predicates logic in the contemporary model theory context; Show examples of decidable and undecidable fragments inside First order logic, offering an original proof of the following theorem: Any formula of First of order logic is decidable if its prenex normal form is in the following form: ∀x1,…,∀xn∃y1,…,∃ymφ; Presenting a theorem that characterizes the validity of First order logic by the tautologicity of Propositional logic, said result is interesting since immediately arises the doubt of how to conciliate said characterization with Alonzo Church’s Undecidability Theorem for First Order Logic.

Terá sentido proteger e responsabilizar penalmente máquinas tal como se protege e responsabiliza penalmente pessoas? Será a Inteligência Artificial das máquinas uma mentalidade artificial, produzida por entidades mentais naturais? Se sim, a artificialidade é decisiva para negar a sua proteção e responsabilidade penais? Se não há verdadeira mentalidade, estará justificada, ainda assim, a sua proteção e responsabilidade penais? E é necessária a posse de mentalidade para haver proteção e responsabilidade penais? Estas são questões fulcrais relativas à relação entre Inteligência Artificial e Direito Penal. Defendo que as razões tradicionais que justificam a proteção e responsabilidade penais não se aplicam às máquinas, pois estas não possuem nem poderão vir a possuir verdadeira mentalidade. Porém, fica em aberto a hipótese de se dissociar o Direito Penal da posse de mentalidade ou, em última instância, a hipótese de o Direito Penal não se fundar na dignidade (para proteger) nem na liberdade (para responsabilizar).

According to the principle of special relativity, the laws of nature are the same for systems at rest and for systems in uniform and rectilinear motion: for the formulation of the laws of nature, the body C and the body C´, which, relative to the former, is in uniform and rectilinear motion, are equivalent. Galileo, in the Dialogue on the Two Greatest Systems of the World, developed the following argument in favor of such a principle: two bodies C and C´, which are in uniform and rectilinear motion in relation to a third body C´´, with the same direction and speed, are at rest in relation to one another; therefore, what is applicable to rest, is applicable to uniform and rectilinear motion. Einstein, in On the Influence of Gravity in the Propagation of Light, generalizes the principle of relativity: all reference bodies C, C´, etc., are equivalent for the formulation of the laws of nature, whatever their state of motion is. The argument is analogous to that of Galileo: two bodies in free fall are at rest in relation to each other; therefore, what is applicable to rest, is applicable to constant acceleration. I argue that those arguments are invalid: to say that rest is shared motion does not mean that rest is, simply, movement. Therefore, one can only conclude that the laws of nature are the same for systems at rest and for systems with shared motion.

Learning equivalence classes of acyclic models with latent and selection variables from multiple datasets with overlapping variables is discussed. The problem of inferring the presence of latent variables, their relation to the observables, and the relation among themselves, is considered. A different approach for identifying causal structures, one that results in much simpler equivalence classes, is provided. It is found that the computational cost is much higher than the procedure implemented, but if datasets are individually of modest dimensionality, it might be doable in practice. From the point of view of search algorithms for optimizing structure, much of the machinery of combinatorial optimization could optimize the penalized composite likelihood score by enforcing constraints such that the independence models over different subsets of variables agree on the overlapping sets.

Os casos de fraqueza da vontade (incontinência) são tidos como paradoxais. Há, pelo menos, uma tensão entre tais casos e a lei psicológica que relaciona avaliações e volições: se julgamos que fazer x é melhor do que fazer y, então queremos fazer x; porém, por vezes, julgamos que fazer x é melhor do que fazer y e, ainda assim, queremos fazer y em vez de x. Como noutras propostas, defendo que a incompatibilidade é aparente. Porém, não rejeito que haja verdadeiros casos de fraqueza da vontade. Proponho que, em tais casos, há uma cisão entre a força psicológica e o conteúdo axiológico das avaliações: o que o agente representa como mais valioso não é o que se encontra mais representado como valioso no agente e, portanto, aquilo que tem eficácia causal. Proponho, ainda, que o sistema volitivo desenvolveu um mecanismo de correção de tais anomalias, pelo qual o agente tem a capacidade de determinar volições de acordo com a avaliação do melhor.

According to the traditional view, the following incompatibility holds true: in reasoning, either there is warrant (certainty) or there is novelty. If there is warrant, there is not novelty: that would be the case of deductive reasoning. If there is novelty, there is not warrant: that would be the case of inductive reasoning. Causal reasoning would belong to the second group because there is novelty and, therefore, there is not warrant in it. I argue that this is false: reasoning may have novelty and, nevertheless, be a deductive one. That is precisely what happens in (some) causal reasoning. And I will develop the following line of argumentation: one thing is to warrant that some state of affairs exists and other thing is to warrant that warrant. So we may have correct deductive reasoning without having certainty of that correction, like in some cases of causal reasoning.

En este artículo realizamos una reconstrucción del Programa original de Hilbert antes del surgimiento de los teoremas limitativos de la tercera década del siglo pasado. Para tal reconstrucción empezaremos por mostrar lo que Torretti llama los primeros titubeos formales de Hilbert, es decir, la defensa por el método axiomático como enfoque fundamentante. Seguidamente, mostraremos como estos titubeos formales se establecen como un verdadero programa de investigación lógico-matemático y como dentro de dicho programa la inquietud por la decidibilidad de los problemas matemáticos y en específico la decidibilidad de la Lógica de primer orden cobra peso. Luego pasamos a analizar como la inquietud por la decibilidad toma lugar dentro del pensamiento filosófico-matemático de Hilbert presentándose como uno de los grandes problemas a los cuales la metamatemática debe encontrar una solución, esto lo hacemos mostrando un contraste con autores, como John von Neumann y Roberto Torretti, quienes de alguna u otra manera no interpretan el problema de la decidibilidad de la Lógica de primer orden como un problema de peso dentro del programa original de Hilbert. Finalmente argumentamos que el resultado meta-teórico de Church puede entenderse como una refutación del optimismo intelectual que permea a todo el programa original de Hilbert.

This paper aims to provide an adequate philosophical groundwork to normativity. More specifîcally, the author argues in favor of its axiological nature: from a philosophical point of view, normativity only becomes intelligible if values are taken into account. Therefore values arise as a necessary condition of normativity. Although not sufficient, values are the decisive condition in distinguishing norms from other relations of the same type. The thought of axiologists like Max Scheler and Nicolai Hartmann is discussed even though their theories do not fully explain how norm and value interrelate.

The ability to identify the mineral composition of rocks and softs is an important tool for the exploration of geological sites. For instance, NASA intends to design robots that are sufficiently autonomous to perform this task on planetary missions. Spectrometer readings provide one important source of data for identifying sites with minerals of interest. Reflectance spectrometers measure intensities of light reflected from surfaces over a range of wavelengths. Spectral intensity patterns may in some cases be sufficiently distinctive for proper identification of minerals or classes of minerals. For some mineral classes, carbonates for example, specific short spectral intervals are known to carry a distinctive signature. Finding similar distinctive spectral ranges for other mineral classes is not an easy problem. We propose and evaluate data-driven techniques that automatically search for spectral ranges optimized for specific minerals. In one set of studies, we partition the whole interval of wavelengths available in our data into sub-intervals, or bins, and use a genetic algorithm to evaluate a candidate selection of subintervals. As alternatives to this computationally expensive search technique, we present an entropy-based heuristic that gives higher scores for wavelengths more likely to distinguish between classes, as well as other greedy search procedures. Results are presented for four different classes, showing reasonable improvements in identifying some, but not all, of the mineral classes tested.