The present study sought to clarify the impact of executive and social functioning on challenging behavior and the downstream influence of challenging behavior on quality of life and functioning in a large transdiagnostic sample. Understanding these relationships is crucial for developing and designing tailored intervention strategies. In a cross-sectional study, parent informants of 2,004 children completed measures of executive and social functioning, challenging behavior, child and family quality of life, and reported on functional impacts of challenging behavior. Using structural (path) (...) modeling, analyses evaluated the associations between executive and social functioning, including emotion regulation and risk avoidance, with overall and specific types of challenging behavior. Structural models also examined the influence of challenging behavior on child and family quality of life, including measures of the immediate and extended environment, and functional impacts on the parent/child as well as interactions with the medical/legal systems. Finally, mediational models explored the direct and indirect effects of executive and social functioning on quality of life and impact measures via challenging behavior. Results indicated that executive functioning accounts for substantial variance (R2 = 0.47) in challenging behavior. In turn, challenging behavior accounts for substantial variance in child and family quality of life (R2 = 0.36) and parent/child impacts (R2 = 0.31). Exploratory mediational models identified direct effects from executive and social functioning measures on quality of life and functional impacts and indirect effects for executive functioning via challenging behavior. These findings support the development of new intervention strategies and suggest the need to measure executive functioning when assessing and tailoring the treatment of challenging behavior in clinical practice. (shrink)

One well-known objection to the principle of maximum entropy is the so-called Judy Benjamin problem, first introduced by van Fraassen. The problem turns on the apparently puzzling fact that, on the basis of information relating an event’s conditional probability, the maximum entropy distribution will almost always assign to the event conditionalized on a probability strictly less than that assigned to it by the uniform distribution. In this article, I present an analysis of the Judy Benjamin problem that can help to (...) make sense of this seemingly odd feature of maximum entropy inference. My analysis is based on the claim that, in applying the principle of maximum entropy, Judy Benjamin is not acting out of a concern to maximize uncertainty in the face of new evidence, but is rather exercising a certain brand of epistemic charity towards her informant. This epistemic charity takes the form of an assumption on the part of Judy Benjamin that her informant’s evidential report leaves out no relevant information. Such a reconceptualization of the motives underlying Judy Benjamin’s appeal to the principle of maximum entropy can help to further our understanding of the true epistemological grounds of this principle and correct a common misapprehension regarding its relationship to the principle of insufficient reason. 1Introduction2The Principle of Maximum Entropy3An Apologia for Judy Benjamin4Conclusion: Entropy and Insufficient Reason. (shrink)

This study examines how meritocracy as a collective social imaginary promoting social justice and fairness reproduces class and caste inequalities and fosters ethical violence. We interrogate discourse of merit in the narratives of the professional–managerial class-in-making at an Indian business school. Empirically, we draw on interviews, full-text responses to a qualitative questionnaire, and a student’s poem. We describe how business school students articulate merit as a neoliberal ethic, emphasizing prudential, enterprising attitudes, and responsibility. However, this positive, aspirational façade of merit (...) masks practices of ethical violence, wherein individuals invoke an ethical principle as grounds for moral condemnation and linguistic injuries. These practices of ethical violence desubjectify disadvantaged students and result in silence as a form of inequality. We contribute to organizational research on inequalities by foregrounding ethical violence and desubjectification. We detail the possibilities of discursive agency in contesting and interrupting ethical violence. (shrink)

Gene expression is an inherently complex process and errors often occur during the transcription and processing of mRNAs. Several surveillance mechanisms have evolved to check the fidelity at each step of mRNA manufacture. Two recent reports describe the identification of a novel pathway in eukaryotes that recognizes and degrades mRNAs that lack a stop codon.1,2 The non‐stop decay mechanism releases ribosomes stalled at the 3′ end of a mRNA and stimulates the exosome to rapidly degrade the transcript. BioEssays 24:785–788, 2002. (...) © 2002 Wiley Periodicals, Inc. (shrink)

String theory has transformed our understanding of geometry, topology and space-time. Thus, for this special issue of Foundations of Physics commemorating “Forty Years of String Theory”, it seems appropriate to step back and ask what we do not understand. As I will discuss, time remains the least understood concept in physical theory. While we have made significant progress in understanding space, our understanding of time has not progressed much beyond the level of a century ago when Einstein introduced the idea (...) of space-time as a combined entity. Thus, I will raise a series of open questions about time, and will review some of the progress that has been made as a roadmap for the future. (shrink)

We argue that in spite of their apparent dissimilarity, the methodologies employed in the a priori and a posteriori assessment of probabilities can both be justified by appeal to a single principle of inductive reasoning, viz., the principle of symmetry. The difference between these two methodologies consists in the way in which information about the single-trial probabilities in a repeatable chance process is extracted from the constraints imposed by this principle. In the case of a posteriori reasoning, these constraints inform (...) the analysis by fixing an a posteriori determinant of the probabilities, whereas, in the case of a priori reasoning, they imply certain claims which then serve as the basis for subsequent probabilistic deductions. In a given context of inquiry, the particular form which a priori or a posteriori reason may take depends, in large part, on the strength of the underlying symmetry assumed: the stronger the symmetry, the more information can be acquired a priori and the less information about the long-run behavior of the process is needed for an a posteriori assessment of the probabilities. In the context of this framework, frequency-based reasoning emerges as a limiting case of a posteriori reasoning, and reasoning about simple games of chance, as a limiting case of a priori reasoning. Between these two extremes, both a priori and a posteriori reasoning can take a variety of intermediate forms. (shrink)

The Ganadbharvad is a philosophical work in which there are profound discussions of eleven salient doctrines. In each of the discussions, one vital Tattva is taken up; and Lord Mahavir discusses it in great detail and clears the doubt of each Ganadhar with the result that each Ganadhar is fully convinced of the truth of the Lord`s argument and becomes his disciple. This book has been written so that people may read it and understand the meaning of the tattvas relating (...) to the soul, the karmas, the five elements, next birth, bondage, deliverance etc. and so that they may realise the true phenomenon of this Universe, may cultivate the trust and may make endeavours to attain the liberations from samsar. (shrink)

Drawing upon rational choice and investor attention theories, we examine how accusations of corporate bribery and subsequent investigations shape market reactions. Using event study methodology to measure loss in firm value for public firms facing bribery investigations from 1978 to 2010, we found that total market penalties amounted to $60.61 billion. We ran moderated multiple regression analysis to examine further the degree to which the unique characteristics of bribery explain variations in market penalties. Companies committing bribery in less corrupt host (...) countries and with the involvement of compromised executives experienced greater market penalties than did other companies. After partitioning share value losses into components for regulatory penalties, class action settlements, and loss to reputation, we found that reputational penalties account for 81.8¢ of every dollar of share value loss. Omission of reputational penalties in rational choice calculus underestimates bribery costs by 4.5 times. The results suggest that firms should not underestimate the importance of market-imposed reputational penalties by merely considering regulator-imposed fines and sanctions. (shrink)

In recent versions of professional genre analysis, context has assumed increasingly critical importance, thus redefining genre as a configuration of text-internal and text-external factors. The emphasis on text-external properties of genre has brought into focus the notion of interdiscursivity as distinct from intertextuality, which is primarily viewed as appropriation of text-internal resources. Drawing evidence from a number of professional contexts, this article explores the nature, function, and use of interdiscursivity in genre theory, defining interdiscursivity as a function of appropriation of (...) generic resources across discursive, professional and cultural practices, which, it is claimed, is central to our understanding of the complexities of genres that are typically employed in professional, disciplinary, and institutional communication. (shrink)

We examine how corporate bribery is impacted by cultural distance between multinational enterprises home and host countries, and organizational distance to core values between MNE entry modes and MNE headquarters. Tension between external and internal legitimacy helps to explain why cultural and organizational distances will affect MNE bribery. The empirical analysis used data from cross-border transactions by MNEs that were sanctioned by US regulatory officials between 1978 and 2011. We find statistical support for all hypotheses capturing main and moderating effects (...) and suggest that MNEs may be seriously risking their legitimacies from transactions in corruption-prone host countries. (shrink)

In the Appendix to the Treatise of Human Nature, Hume famously recants his position on personal identity. There he confesses: “upon a strict review of the section concurring personal identity I find myself involv’d in such a labyrinth that... I neither know how to correct my former opinions, nor how to render them consistent.” By his own admission, then, something has gone wrong in Hume’s account of personal identity, something that, at least to his eyes, did not go wrong in (...) his accounts of body and necessary connection. For those accounts were not grossly inconsistent or patently absurd. The case is different, however, with personal identity. There his philosophical enterprise suffers shipwreck, and it is important to understand why. Unfortunately, however, Hume confesses that he finds his former opinions false as well as inconsistent, but neglects to specify how or why he came to this conclusion. This paper is an attempt to address just that question. (shrink)

This essay deals with the manner in which Salman Rushdie’s works engage with the heterogeneous logics of ethics and aesthetics. Drawing upon the work of Jacques Rancière it is argued that Rushdie neutralizes the two by introducing what Rancière calls a dissensus in the ethical-aesthetic hierarchy. The dissensus works on a principle of ‘excess’ so that within the domain of aesthetics the ethical is pushed to its limits. The order of desire (aesthetics) and the order of knowledge (ethics) are no (...) longer seen as hierarchical and mutually exclusive categories. By examining two versions of an unpublished novel by Rushdie (‘Madame Rama’) it is suggested that Bollywood cinema functions as a mode in which the two orders come together. In this early and mercifully unpublished novel, one finds the beginnings of Rushdie’s belief that works of art are sites of ideological and ethical contestations. (shrink)

This article provides an Austrian overview of the inflation versus deflation debate which has captured the attention of the economics profession in the years following the US housing bust. Much of the Austrian analysis of this debate has focused on the massive expansion of the Federal Reserve’s balance sheet and attendant creation of new reserves. Several Austrian economists have predicted that the creation of new reserves will cause a massive increase in inflation. The money multiplier theory, on which these predictions (...) are based, is criticized and an overview of the Austrian business cycle theory is provided to explain why banks are reluctant to issue new credit. Finally, an analysis of the politics of deflation is provided and a class theory is presented to explain why a policy of controlled credit deflation is more likely than a policy that would result in mass inflation or hyperinflation. (shrink)

This article responds to Terry Eagleton's claim that Spivak's latest book, A Critique of Postcolonial Reason, works against the intent of postcolonial criticism. Reading the work as a search for a just representational strategy, we explore the implications of Spivak's engagement with philosophy - Kant, Hegel, and Marx. As a disciplinary machine, philosophy produces Western subjects who are engendered by simultaneously including and excluding the other. Working through this production of the double location of the 'other' we suggest that systematic (...) thought is inhabited by an absence that is present within, a disturbing otherness that ultimately questions authority and stability, and opens up the question of politics and representation. Drawing Spivak into the representational problematic opened up by Lyotard, we suggest that a responsible postcolonial intervention can be performed in the difficult exergue between representability and unrepresentability. In this account, representation is open to invention, to finding new idioms for articulating otherness. (shrink)

Most of us know of God only as "Our Father in Heaven". However, there is the other view, which declares that "I and my Father are one." That is a very bold view, which only the daring dare to embrace. Proclaimed by fearless thinkers in all ages, this professed Godhood is no one person's exclusive domain, as some would have you believe, but the common property of one and all. Whatever be your station in life, truth remains that you are (...) God. Everything else that you hold yourself to be is pure ignorance. This book is the bold wake-up call to make you realize who you are. Like a distant thunder, we hear a voice rolling down from the past "Never forget the glory of human nature. We are the Greatest God, that ever was, or ever will be. Christs and Buddhas are but waves, on the boundless ocean which I am"; but its sound is getting dimmer; its echoes lost in the din and clutter of fanaticism and materialism. This book is the clarion call that resounds the bugle of that age-old theme once again and with a vengeance. A vengeance that stems from rationality, reasons, and the added weight of discoveries in modern sciences; discoveries, which are all found to resonate with that grand ancient truth. Unlike anything that you may have read, this book questions your most fundamental concepts. Be prepared to abandon all preconceived notions that you may hold about the Self and the Universe. This iconoclastic book shatters all delusions, and will truly revolutionize the way your perceive yourself and the world. (shrink)

In this paper, we outline the foundations of the time invariant, non-unitary covering of quantum chemistry known as hadronic chemistry, we illustrate its validity by reviewing the exact representations of the binding energies of the Hydrogen and water molecules, and present new advances.

This paper presents a new solution to the well-known exchange paradox, or what is sometimes referred to as the two-envelope paradox. Many recent commentators have analyzed the paradox in terms of the agent’s biased concern for the contents of his own arbitrarily chosen envelope, claiming that such bias violates the manifest symmetry of the situation. Such analyses, however, fail to make clear exactly how the symmetry of the situation is violated by the agent’s hypothetical conclusion that he ought to switch (...) envelopes on the assumption that his own envelope contains some specific amount of money. In this paper, I offer an explanation of this fact based on the idea that the agent’s deliberations are not only constrained by the epistemic symmetry reflected in the agent’s uniform ignorance as to the contents of the two envelopes, but also by a deeper methodological symmetry that manifests itself in the intuition that the two envelopes constitute equally legitimate sources of potential information. I interpret this intuition as implying that the agent’s final decision should reflect a point of rational equilibrium arrived at through an iterated process of counterfactual self-reflection, whereby the agent takes account of what he would have thought had he instead chosen the other envelope. I provide a formal model of this method of counterfactual self-reflection and show, in particular, that it cannot issue in the paradoxical conclusion that the agent ought to switch regardless of how much money is in his envelope. In this way, by correcting for the bias in the agent’s reasoning, the paradox is resolved. (shrink)

Judgments of symmetry lay at the heart of the classical theory of probability. It was by direct appeal to the symmetries exhibited by the processes underlying simple games of chance that the earliest theorists of probability were able to justify the initial assumptions of equiprobability which allowed them to compute the probabilities of more complex events using combinatorial methods, i.e., by simply counting cases. Nevertheless, in spite of the role that symmetry played in the earliest writings on the subject, in (...) light of the fact it is only in highly contrived settings that a direct appeal to symmetries can suffice to determine the probabilities of events, many philosophers have been led to conclude that the concept of symmetry itself has, at best, a limited role to play in a general theory of probability. In this essay, I argue that this view of the matter is mistaken, and that judgments of symmetry, in fact, have an indispensible role to play in all probabilistic reasoning. In chapter 1, I provide a detailed account of symmetry-based reasoning and argue against the view that the judgments of relevance on which such reasoning is based must be construed in subjective terms if symmetry-based reasoning is to be applied to deterministic processes. In chapter 2, I argue that the two most plausible proposals for how to avoid an appeal to symmetry in the assignment of probabilities (viz., those which are based on a priori principles of epistemic conservatism or the observed frequencies of events) must themselves rely on implicit assumptions of symmetry if they are to defend themselves against the charges of incoherency and arbitrariness. In chapter 3, I consider a decision-theoretic example of symmetry-based reasoning, in which the appeal to symmetry arises in the context of an agent's choice of a deliberative methodology. In this context, the principle of symmetry amounts to the requirement that the agent avoid adopting a biased deliberative methodology, i.e., one which treats two equally legitimate sources of information differently. In the specific context of the exchange paradox, I propose an account of how biased information is to be handled, which, despite suffering from some important defects, does, I believe, capture some of our general intuitions about how a rational agent ought to adjust his expectations to correct for the effects of bias. (shrink)

Biodiesel was produced by transesterification of waste olive oil with methanol and Novozym®435. The effect of the molar ratio of methanol to triolein, mode of methanol addition, reaction temperature, and mixing speed on biodiesel yield was determined. The effect of different acyl acceptors and/or solvents on biodiesel yield was also evaluated. Finally, the efficacy of Novozym®435 was determined by reusing the enzyme after washing it with a solvent.

Japan has more robots than any other country with robots contributing to many areas of society, including manufacturing, healthcare, and entertainment. However, few studies have examined Japanese attitudes toward robots, and none has used implicit measures. This study compares attitudes among the faculty of a US and a Japanese university. Although the Japanese faculty reported many more experiences with robots, implicit measures indicated both faculties had more pleasant associations with humans. In addition, although the US faculty reported people were more (...) threatening than robots, implicit measures indicated both faculties associated weapons more strongly with robots than with humans. Despite the media’s hype about Japan’s robot ‘craze,’ response similarities suggest factors other than attitude better explain robot adoption. These include differences in history and religion, personal and human identity, economic structure, professional specialization, and government policy. Japanese robotics offers a unique reference from which other nations may learn. (shrink)

This journal's well-intentioned consideration of the arts has turned out to be quite the Pandora's box. As soon as we broach the subject of aesthetics, we are already in the realm of ideology; as soon as we impose the frame of scientific inquiry upon any subject, we invoke another kind of ideology. The previous issues in this series have depicted the unfolding of an ideological clash of cultures between sciences and the humanities, enough to make C.P. Snow blush. For the (...) time being, this is an unavoidable condition; yet the more we remain aware of it, the further we may push our insights. (shrink)

Merging logic and mathematics in deductive inference-an innovative, cutting-edge approach. Optimization methods for logical inference? Absolutely, say Vijay Chandru and John Hooker, two major contributors to this rapidly expanding field. And even though "solving logical inference problems with optimization methods may seem a bit like eating sauerkraut with chopsticks... it is the mathematical structure of a problem that determines whether an optimization model can help solve it, not the context in which the problem occurs." Presenting powerful, proven optimization techniques (...) for logic inference problems, Chandru and Hooker show how optimization models can be used not only to solve problems in artificial intelligence and mathematical programming, but also have tremendous application in complex systems in general. They survey most of the recent research from the past decade in logic/optimization interfaces, incorporate some of their own results, and emphasize the types of logic most receptive to optimization methods-propositional logic, first order predicate logic, probabilistic and related logics, logics that combine evidence such as Dempster-Shafer theory, rule systems with confidence factors, and constraint logic programming systems. Requiring no background in logic and clearly explaining all topics from the ground up, Optimization Methods for Logical Inference is an invaluable guide for scientists and students in diverse fields, including operations research, computer science, artificial intelligence, decision support systems, and engineering. (shrink)

Legislative writing, which is one of the key genres in the practice of law, has mostly been overlooked in pedagogic applications in English for Legal Communication (ELC), even though more than any other professional writing, it demonstrates very typical and distinctive use of linguistic and other semiotic resources, including some of the specific rhetorical conventions and constraints. However, it is surprising that despite its distinctive prominence in legal practice, it has never figured in English for Legal Communication programmes. It seems (...) to be the result of pedagogic convenience rather than curriculum need. In this paper, I would like to argue for the inclusion of legislative genres in English for Legal Communication curriculum design as input to teaching materials, to make it easier for learners to understand and interpret other forms of legal communication, such as cases, judgements, contracts, agreements, and even courtroom interaction. (shrink)

This study aims to investigate how the English Language used by the Indian Railways is different from other registers of English, and most importantly what is the effect of this register of English upon the common people. In other words, the present study aims at viewing the variety of language used by the Indian Railway as an independent register. For the purpose of investigation, a stylistic analysis is carried out. The data for the current study are collected from the platform, (...) directives at railway premises and inside the railway-coaches. Platform announcements have been collected from various railway stations across the country. Some amount of data has been collected from the directives inside the railway coaches. (shrink)

Broadening access to both computational and educational resources is crit- ical to diffusing machine learning (ML) innovation. However, today, most ML resources and experts are siloed in a few countries and organizations. In this article, we describe our pedagogical approach to increasing access to applied ML through a massive open online course (MOOC) on Tiny Machine Learning (TinyML). We suggest that TinyML, applied ML on resource-constrained embedded devices, is an attractive means to widen access because TinyML leverages low-cost and globally (...) accessible hardware and encourages the development of complete, self-contained applications, from data collection to deployment. To this end, a collaboration between academia and industry produced a four part MOOC that provides application-oriented instruction on how to develop solutions using TinyML. The series is openly available on the edX MOOC platform, has no prerequisites beyond basic programming, and is designed for global learners from a variety of backgrounds. It introduces real-world applications, ML algorithms, data-set engineering, and the ethi- cal considerations of these technologies through hands-on programming and deployment of TinyML applications in both the cloud and on their own microcontrollers. To facili- tate continued learning, community building, and collaboration beyond the courses, we launched a standalone website, a forum, a chat, and an optional course-project com- petition. We also open-sourced the course materials, hoping they will inspire the next generation of ML practitioners and educators and further broaden access to cutting-edge ML technologies. (shrink)

There are complex considerations when planning to disclose an attenuated psychosis syndrome diagnosis. In this review, we evaluate ethical, legal, and clinical perspectives as well as caveats related to full, non- and partial disclosure strategies, discuss societal implications, and provide clinical suggestions. Each of the disclosure strategies is associated with benefits as well as costs/considerations. Full disclosure promotes autonomy, allows for the clearest psychoeducation about additional risk factors, helps to clarify and/or correct previous diagnoses/treatments, facilitates early intervention and bolsters communication (...) between providers but there are important considerations involving heritability, comorbidity, culture, and stigma. Non-disclosure advances nonmaleficence by limiting stigma and stress, and confusion in a sensitive developmental period but is complicated by varying patient preferences and the possibility that, as new treatments without adverse effects become available, the risk with false positives no longer justifies the accompanying loss of autonomy. Partial disclosure balances ethical considerations by focusing on symptoms instead of labels, but evidence that laypersons may interpret this information as a pseudo-diagnosis and that symptoms alone also contribute to stigma limits the efficacy of this approach. In addition, there are notable societal considerations relating to disclosure involving conservatorship, the reach of insurance companies, and discrimination. We advocate a hybrid approach to disclosure and recommend future research aimed at understanding the effects of stigma on clinical course and a renewed focus on those help-seeking cases that do not transition but remain clinically relevant. (shrink)

In this paper, we provide a Bayesian analysis of the well-known surprise exam paradox. Central to our analysis is a probabilistic account of what it means for the student to accept the teacher's announcement that he will receive a surprise exam. According to this account, the student can be said to have accepted the teacher's announcement provided he adopts a subjective probability distribution relative to which he expects to receive the exam on a day on which he expects not to (...) receive it. We show that as long as expectation is not equated with subjective certainty there will be contexts in which it is possible for the student to accept the teacher's announcement, in this sense. In addition, we show how a Bayesian modeling of the scenario can yield plausible explanations of the following three intuitive claims: (1) the teacher's announcement becomes easier to accept the more days there are in class; (2) a strict interpretation of the teacher's announcement does not provide the student with any categorical information as to the date of the exam; and (3) the teacher's announcement contains less information about the date of the exam the more days there are in class. To conclude, we show how the surprise exam paradox can be seen as one among the larger class of paradoxes of doxastic fallibilism, foremost among which is the paradox of the preface. (shrink)

The parking of cars is a globally recognized problem, especially at locations where there is a high demand for empty parking spaces. Drivers tend to cruise additional distances while searching for empty parking spaces during peak hours leading to problems, such as pollution, congestion, and driver frustration. Providing short-term predictions of parking availability would facilitate the driver in making informed decisions and planning their arrival to be able to choose parking locations with higher availability. Therefore, the aim of this study (...) is to provide short-term predictions of available parking spaces with a low volume of data. The open parking lot provides parking spaces free of charge and one such parking lot, located beside a shopping center, was selected for this study. Parking availability data for 21 days were collected where 19 days were used for training, while multiple periods of the remaining 2 days were used to test and evaluate the prediction methods. The test dataset consists of data from a weekday and a weekend. Based on the reviewed literature, three prediction methods suitable for short-term prediction were selected, namely, long short-term memory, seasonal autoregressive integrated moving average with exogenous variables, and the Ensemble-based method. The LSTM method is a deep learning-based method, while SARIMAX is a regression-based method, and the Ensemble method is based on decision trees and random forest to provide predictions. The performance of the three prediction methods with a low volume of data and the use of visitor trends data as an exogenous variable was evaluated. Based on the test prediction results, the LSTM and Ensemble-based methods provided better short-term predictions at multiple times on a weekday, while the Ensemble-based method provided better predictions over the weekend. However, the use of visitor trend data did not facilitate improving the predictions of SARIMAX and the Ensemble-based method, while it improved the LSTM prediction for the weekend. (shrink)

Greek antiquity saw the development of two distinct systems of logic: Aristotle’s theory of the categorical syllogism and the Stoic theory of the hypothetical syllogism. Some ancient logicians argued that hypothetical syllogistic is more fundamental than categorical syllogistic on the grounds that the latter relies on modes of propositional reasoning such asreductio ad absurdum. Peripatetic logicians, by contrast, sought to establish the priority of categorical over hypothetical syllogistic by reducing various modes of propositional reasoning to categorical form. In the 17th (...) century, this Peripatetic program of reducing hypothetical to categorical logic was championed by Gottfried Wilhelm Leibniz. In an essay titledSpecimina calculi rationalis, Leibniz develops a theory of propositional terms that allows him to derive the rule ofreductio ad absurdumin a purely categorical calculus in which every proposition is of the formA is B. We reconstruct Leibniz’s categorical calculus and show that it is strong enough to establish not only the rule ofreductio ad absurdum, but all the laws of classical propositional logic. Moreover, we show that the propositional logic generated by the nonmonotonic variant of Leibniz’s categorical calculus is a natural system of relevance logic known as RMI$_{{}_ \to ^\neg }$. (shrink)