DEVELOPMENT OF LOGIC IN INDIA: SIGNIFICANCE OF 'THE DUOLOGUE BETWEEN PĀYĀSI AND KASSAPA' ("LONG DISCOURSES")

ABSTRACT 'The Duologue of King/Governor Pāyāsi' ("Long Discourses") has long been recognised as a source for the proto-materialism current at the time of the Buddha. What needs to be stressed is the significance of the text as a pointer to the development of Logic in India. Perception (observation and experiment employing the joint method of agreement and difference), which is an accepted method of experimental enquiry, and reasoning from analogy, which can lead at best to a probable conclusion - these two are the only means employed to settle the dispute concerning the existence of the other-world. The Jain version of the same duologue-cum-parable, though varying in minor details regarding the name and identity of the monk refuting the king/governor, contains the same contrast, namely, perception versus analogical reasoning. There can be little doubt that the original parable was conceived with a view to asserting the existence of the other-world. In the Kaṭha Upaniṣad (sixth century BCE), an earlier Brahmanical text, however, instead of argument by analogy, verbal testimony (śabda) was invoked to settle the same point. Naciketas is assailed by doubt about the existence of a person after his or her death. The authority of Yama, the Pluto of Indian mythology, is invoked to convince him that the other-world does exist. Thus, the three parables taken together exhibit three means of knowledge in operation: verbal testimony and argument by analogy pitted against perception.

Classificações de signos de C.S.Peirce: de ‘On the Logic of Science’ ao ‘Syllabus of Certain Topics of Logic’

As classificações dos signos de C.S.Peirce começam a ser desenvolvidas em 1865 e se estendem a até, pelo menos, 1909. Vou apresentar o período que tem início em 1865, e possui dois momentos de intensa produção - "On a New List of Categories" e "On the Algebra of Logic: a contribution to the philosophy of notation". Em seguida apresento as dez classes de signos, uma morfologia que aparece no "Syllabus of Certain Topics of Logic", e é desenvolvida a partir de 1903. Meu propósito aqui é familiarizar o leitor com as intrincadas classificações sígnicas de Peirce.

One reason, several logics

Humans have used arguments for defending or refuting statements long before the creation of logic as a specialized discipline. This can be interpreted as the fact that an intuitive notion of "logical consequence" or a psychic disposition to articulate reasoning according to this pattern is present in common sense, and logic simply aims at describing and codifying the features of this spontaneous capacity of human reason. It is well known, however, that several arguments easily accepted by common sense are actually "logical fallacies", and this indicates that logic is not just a descriptive, but also a prescriptive or normative enterprise, in which the notion of logical consequence is defined in a precise way and then certain rules are established in order to maintain the discourse in keeping with this notion. Yet in the justification of the correctness and adequacy of these rules commonsense reasoning must necessarily be used, and in such a way its foundational role is recognized. Moreover, it remains also true that several branches and forms of logic have been elaborated precisely in order to reflect the structural features of correct argument used in different fields of human reasoning and yet insufficiently mirrored by the most familiar logical formalisms.

THE FORMAL AND THE FORMALIZED: THE CASES OF SYLLOGISTIC AND SUPPOSITION THEORY

As a discipline, logic is arguably constituted of two main sub-projects: formal theories of argument validity on the basis of a small number of patterns, and theories of how to reduce the multiplicity of arguments in non-logical, informal contexts to the small number of patterns whose validity is systematically studied (i.e. theories of formalization). Regrettably, we now tend to view logic 'proper' exclusively as what falls under the first sub-project, to the neglect of the second, equally important sub-project. In this paper, I discuss two historical theories of argument formalization: Aristotle's syllogistic theory as presented in the "Prior Analytics", and medieval theories of supposition. They both illustrate this two-fold nature of logic, containing in particular illuminating reflections on how to formalize arguments (i.e. the second sub-project). In both cases, the formal methods employed differ from the usual modern technique of translating an argument in ordinary language into a specially designed symbolism, a formal language. The upshot is thus a plea for a broader conceptualization of what it means to formalize.

THE LOGICAL SYSTEM OF FREGE'S GRUNDGESTZE: A RATIONAL RECONSTRUCTION

This paper aims at clarifying the nature of Frege's system of logic, as presented in the first volume of the Grundgesetze . We undertake a rational reconstruction of this system, by distinguishing its propositional and predicate fragments. This allows us to emphasise the differences and similarities between this system and a modern system of classical second-order logic.

Kant and zeno of elea: historical precedents of the "sceptical method"

For Kant's interpretation of Zeno in KrV A502-507/B530-535, scholars have usually referred to Plato's Phaedrus (261d); in reality the sources Kant uses are, on one hand, Brucker (who depends in turn on the pseudo-Aristotelian De Melisso, Xenophane, et Gorgia, 977 b 2-21), and, on the other, Plato's Parmenides (135e6-136b1) and Proclus' commentary on it, as quoted by Gassendi in a popular textbook he wrote on the history of logic.

Assessment of a consultation-liaison psychiatry and psychology health care program

OBJECTIVE: To investigate the relevance of subjective criteria adopted by a psychiatry and psychology consultation-liaison service, and their suitability in the evaluation of case registries and objective results. METHODS: Semi-structured interviews were conducted and all supervisors of the university hospital service were interviewed. Routinely collected case registries were also reviewed. Standardized assessment with content analysis for each category was carried out. RESULTS: The results showed distortions in the adopted service focus (doctor-patient relationship) and consultant requests. This focus is more on consulting physician-oriented interventions than on patients. DISCUSSION: Evaluation of the relevance of service criteria could help promoting quality assessment of the services provided, mainly when objective criteria have not yet been established to assure their suitability.

Fuzzy logic applied to the modeling of water dynamics in an Oxisol in northeastern Brazil

Modeling of water movement in non-saturated soil usually requires a large number of parameters and variables, such as initial soil water content, saturated water content and saturated hydraulic conductivity, which can be assessed relatively easily. Dimensional flow of water in the soil is usually modeled by a nonlinear partial differential equation, known as the Richards equation. Since this equation cannot be solved analytically in certain cases, one way to approach its solution is by numerical algorithms. The success of numerical models in describing the dynamics of water in the soil is closely related to the accuracy with which the water-physical parameters are determined. That has been a big challenge in the use of numerical models because these parameters are generally difficult to determine since they present great spatial variability in the soil. Therefore, it is necessary to develop and use methods that properly incorporate the uncertainties inherent to water displacement in soils. In this paper, a model based on fuzzy logic is used as an alternative to describe water flow in the vadose zone. This fuzzy model was developed to simulate the displacement of water in a non-vegetated crop soil during the period called the emergency phase. The principle of this model consists of a Mamdani fuzzy rule-based system in which the rules are based on the moisture content of adjacent soil layers. The performances of the results modeled by the fuzzy system were evaluated by the evolution of moisture profiles over time as compared to those obtained in the field. The results obtained through use of the fuzzy model provided satisfactory reproduction of soil moisture profiles.

Application of fuzzy logic for the evaluation of livestock slaughtering

The fuzzy logic admits infinite intermediate logical values between false and true. With this principle, it developed in this study a system based on fuzzy rules, which indicates the body mass index of ruminant animals in order to obtain the best time to slaughter. The controller developed has as input the variables weight and height, and as output a new body mass index, called Fuzzy Body Mass Index (Fuzzy BMI), which may serve as a detection system at the time of livestock slaughtering, comparing one another by the linguistic variables "Very Low", "Low", "Average ", "High" and "Very High". For demonstrating the use application of this fuzzy system, an analysis was made with 147 Nellore beeves to determine Fuzzy BMI values for each animal and indicate the location of body mass of any herd. The performance validation of the system was based on a statistical analysis using the Pearson correlation coefficient of 0.923, representing a high positive correlation, indicating that the proposed method is appropriate. Thus, this method allows the evaluation of the herd comparing each animal within the group, thus providing a quantitative method of farmer decision. It was concluded that this study established a computational method based on fuzzy logic that mimics part of human reasoning and interprets the body mass index of any bovine species and in any region of the country.

Speed Control of an Autonomous Mobile Robot: Comparison between a PID Control and a Control Using Fuzzy Logic

An Autonomous Mobile Robot battery driven, with two traction wheels and a steering wheel is being developed. This Robot central control is regulated by an IPC, which controls every function of security, steering, positioning localization and driving. Each traction wheel is operated by a DC motor with independent control system. This system is made up of a chopper, an encoder and a microcomputer. The IPC transmits the velocity values and acceleration ramp references to the PIC microcontrollers. As each traction wheel control is independent, it's possible to obtain different speed values for each wheel. This process facilities the direction and drive changes. Two different strategies for speed velocity control were implemented; one works with PID, and the other with fuzzy logic. There were no changes in circuits and feedback control, except for the PIC microcontroller software. Comparing the two different speed control strategies the results were equivalent. However, in relation to the development and implementation of these strategies, the difficulties were bigger to implement the PID control.

Simulation of Active Control Using Fuzzy Logic Applied to a Pulse Combustor

This work analyzes an active fuzzy logic control system in a Rijke type pulse combustor. During the system development, a study of the existing types of control for pulse combustion was carried out and a simulation model was implemented to be used with the package Matlab and Simulink. Blocks which were not available in the simulator library were developed. A fuzzy controller was developed and its membership functions and inference rules were established. The obtained simulation showed that fuzzy logic is viable in the control of combustion instabilities. The obtained results indicated that the control system responded to pulses in an efficient and desirable way. It was verified that the system needed approximately 0.2 s to increase the tube internal pressure from 30 to 90 mbar, with an assumed total delay of 2 ms. The effects of delay variation were studied. Convergence was always obtained and general performance was not affected by the delay. The controller sends a pressure signal in phase with the Rijke tube internal pressure signal, through the speakers, when an increase the oscillations pressure amplitude is desired. On the other hand, when a decrease of the tube internal pressure amplitude is desired, the controller sends a signal 180º out of phase.

The death and resurrection of 'economics with psychology': remarks from a methodological standpoint

One of the merits of contemporary economic analysis is its capacity to offer accounts of choice behavior that dispense with details of the complex decision machinery. The starting point of this paper is the concern with the important methodological debate about whether economics might offer accurate predictions and explanations of actual behavior without any reference to psychological presuppositions. Inspired by an exercise of rational reconstruction of ideas, I aim to offer an interpretation of the process of freeing economic analysis from psychology at the end of the 19th century and the contemporary resurrection of behavioral approaches in the late 1980s.

Mental Logic and the Denials of Conjunctions and Disjunctions

ABSTRACT: The mental models theory predicts that, while conjunctions are easier than disjunctions for individuals, when denied, conjunctions are harder than disjunctions. Khemlani, Orenes, and Johnson-Laird proved that this prediction is correct in their work of 2014. In this paper, I analyze their results in order to check whether or not they really affect the mental logic theory. My conclusion is that, although Khemlani et al.'s study provides important findings, such findings do not necessarily lead to questioning or to rejecting the mental logic theory.