David Pearce

We give an account of stable reasoning, a recent and novel approach to problem solving from a formal, logical point of view. We describe the underlying logic of stable reasoning and illustrate how it is used to model different domains and solve practical reasoning problems. We discuss some of the main differences with respect to reasoning in classical logic and we examine an ongoing research programme for the rational reconstruction of human knowledge that may be considered a successor to the logical empiricists’ programme of the mid-twentieth century.

Near the end of 2015, Luis Fariñas del Cerro officially retired as directeur de recherche in the Centre National de Recherche Scientifique (CNRS) and became an Emeritus researcher of the CNRS. The present special issue is a Festschrift in his honour to celebrate Luis’s achievements in science, both as an outstanding scholar as well as a remarkable and highly successful organiser, administrator and leader in science and technology policy and management, in particular as the founder of the Journal of Applied Non-Classical Logics. The issue contains 13 scientific contributions by 32 authors, among them Luis’s colleagues, former students and friends. Preceding versions of these papers were presented at the international workshop ‘Logical Reasoning and Computation’ that was held at IRITInstitut de Recherche en Informatique de Toulouse, Université Paul Sabatier, Toulouse, on 3–4 March 2016. The present introduction contains a short scientific biography describing the many different areas of logic and computation where Luis contributed significant advances.

"This book constitutes the proceedings of the 1994 European Workshop on Logics in Artificial Intelligence, held at York, UK in September 1994. The 24 papers presented were selected from a total of 79 submissions; in addition there are two abstracts of invited talks and one full paper of the invited presentation by Georg Gottlob. The papers point out that, with the depth and maturity of formalisms and methodologies available in AI today, logics provide a formal basis for the study of the whole field of AI. The volume offers sections on nonmonotonic reasoning, automated reasoning, logic programming, knowledge representation, and belief revision."--PUBLISHER'S WEBSITE.

D.P. It will technically be possible to get rid of all suffering within a century or two. Its abolition would be practical only if it were agreed in the sense of something like the moon program or the human genome project – if there was a degree of social consensus. There are certainly technological obstacles, but they are dwarfed by the ethical-ideological ones. Many people’s negative reaction to the idea of a world without suffering comes from a fear that someone is going to be manipulating and controlling them. Partly, too, the abolition of suffering seems to make a mockery of one’s life projects. Most of us spend the greater part of our lives seeking happiness for ourself and others we care about. But we do so in extremely inefficient and in many cases self-defeating ways. This is a problem with existing human society. Even though we have made extraordinary progress technologically and medically, we aren’t any happier than our ancestors. Even if we could arrange society in the most utopian way imaginable, there would be some people who would still be depressed and anxious. There would be some people who would be consumed by jealousy or unhappy love affairs. No amount of environmental reform or manipulation is going to get rid of suffering. Only biotechnology can eradicate its neural substrates

Stepping on a strongly electrified grid is highly aversive. A desperately hungry rat - even a rat who hasn't eaten for 10 days - won't run across an electrified cage-floor to reach a food-source: the shocks are too painful. But a rat with electrodes implanted in its neural reward circuitry will cross the grid, repeatedly, to gain the chance to self-stimulate its pleasure centres. Direct electrical stimulation of the mesolimbic dopamine system is so overpoweringly delightful that the anticipated reward eclipses the immediate pain

"Over the past half billion years, life on Earth has been governed by the pleasure pain axis. Nature is typically "red in tooth and claw". Consequently, life has typically been "nasty, brutish and short". However, a major evolutionary transition lies ahead. Natural selection has evolved organic robots with the capacity to rewrite their own source code. Humans will shortly be able to redesign our own reward circuitry, decommission natural selection, design compassionate ecosystems, and abolish suffering throughout the living world