•  74
    In this address, Leslie Allan shares his early experiences and how they shape his humanist outlook today. He then outlines what he considers to be the three core principles underlying the humanist world view and illustrates their application with historical and contemporary examples. He concludes by drawing upon each of these principles to tease out what it means to live a good life; a life of meaning and purpose.
  •  502
    Leslie Allan demonstrates how human rights are unproblematic for utilitarian moral theory and how, upon consideration, utilitarianism turns out to be the best theory for justifying human rights. Using case studies of historical and contemporary human rights conventions and recent psychological research, he argues how our concept of human rights is founded on the satisfaction of fundamental human needs and the consequences for human happiness.
  •  65
    Leslie Allan reviews Professor Losee's tracing of the history of the philosophy of science from its beginning with Aristotle in Ancient Greece, through the Middle Ages and the Enlightenment to the work of contemporary philosophers. In this review, Allan also provides a summary of each chapter and commentary on Losee's analysis.
  •  1409
    This tutorial is for beginners wanting to learn the basics of propositional logic; the simplest of the formal systems of logic. Leslie Allan introduces students to the nature of arguments, validity, formal proofs, logical operators and rules of inference. With many examples, Allan shows how these concepts are employed through the application of three different methods for proving the formal validity of arguments.
  •  10451
    Donald Hoffman proposed a bold theory—that objects do not exist independently of us perceiving them and that all that really exists is conscious agents. In this critical review, Leslie Allan examines the three core components of Hoffman's new idealism. He proposes solutions to linguistic absurdities suffered by Hoffman's theory before considering its most serious problems. These include oversimplifications of evolutionary theory, self-refutation, heuristic sterility and dependence on scientific …Read more
  •  1837
    In his seminal essay, 'Two Concepts of Rules', John Rawls draws a central distinction between justifying a practice and justifying a particular action falling under it. In this review, Leslie Allan walks through Rawls's essay, highlighting his key arguments for a strengthened version of rule utilitarianism and reflecting on the lasting influence of his analysis.
  •  1793
    Subjectivists claim that the absence of a theological or metaphysical grounding to moral judgements renders them all as simply statements about our subjective wants and preferences. Leslie Allan argues that the subjectivists' case rests on a misunderstanding of the nature of moral objectivity. He presents the view that subjectivists mistakenly counterpoise the ideal of moral objectivity with the expression of individual preferences. Being objective in moral deliberation, Allan argues, should be …Read more
  •  497
    In his seminal essay, Harry Frankfurt argued that our exercise of free will and allocation of moral responsibility do not depend on us being able to do other than we did. Leslie Allan defends this moral maxim from Frankfurt's attack. Applying his character-based counterfactual conditional analysis of free acts to Frankfurt's counterexamples, Allan unpacks the confusions that lie at the heart of Frankfurt's argument. The author also explores how his 4C compatibilist theory measures up against Fra…Read more
  •  3953
    The author mounts a case against the libertarian and hard determinist's thesis that free will is impossible in a deterministic world. He charges incompatibilists with misconstruing ordinary 'free will' talk by overlaying common language with their own metaphysical presuppositions. Through a review of ordinary discourse and recent developments in jurisprudence and the sciences, he draws together the four key factors required for an act to be free. He then puts his 4C theory to work in giving a cr…Read more
  •  26177
    Enlightenment philosopher, René Descartes, set out to establish what could be known with certainty, untainted by a deceiving demon. With his method of doubt, he rejected all previous beliefs, allowing only those that survived rigorous scrutiny. In this essay, Leslie Allan examines whether Descartes's program of skeptical enquiry was successful in laying a firm foundation for our manifold beliefs. He subjects Descartes's conclusions to Descartes's own uncompromising methodology to determine wheth…Read more
  •  15581
    The ontological argument for the existence of God has enjoyed a recent renaissance among philosophers of religion. Alvin Plantinga's modal version is perhaps the most notable example. This essay critically examines Plantinga's rendition, uncovering both its strengths and weaknesses. The author concludes that while the argument is probably formally valid, it is ultimately unsound. Nonetheless, Plantinga's version has generated much interest and discussion. The author spends some time uncovering t…Read more
  •  3890
    The materialist version of the mind/brain identity theory has met with considerable challenges from philosophers of mind. The author first dispenses with a popular objection to the theory based on the law of indiscernibility of identicals. By means of discussing the vexatious problem of phenomenal qualities, he explores how the debate may be advanced by seeing each dualist and monist ontology through the lens of an evolutionary epistemology. The author suggests that by regarding each ontology as…Read more
  •  2276
    The author contends that classifying theories in the field of meta-ethics along a single dimension misses important nuances in each theory. With the increased sophistication and complexity of meta-ethical analyses in the modern era, the traditional cognitivist–non-cognitivist and realist–anti-realist categories no longer function adequately. The author categorizes the various meta-ethical theories along three dimensions. These dimensions focus on the linguistic analysis offered by each theory, i…Read more
  •  9866
    Meta-ethics is the area of philosophy in which thinkers explore the language and nature of moral discourse and its relations to other non-moral areas of life. In this introduction to the discipline written explicitly for novices, Leslie Allan outlines the key questions and areas of analysis in contemporary meta-ethics. In clear, tabular format, he summarizes the core concepts integral to each of the major meta-ethical positions and the strengths of each view. To prompt further thinking and readi…Read more
  •  1593
    In this comprehensive work on theories of rationality, Leslie Allan builds on the seminal insights of Imre Lakatos. Allan begins by critically reviewing Lakatos' theory of rationality (MSRP) and his meta-theory of rationality (MHRP) and suggesting improvements to his scheme. Allan's main task is developing a theory of rationality that avoids Lakatos' Achilles' heel; the presupposition that science is a rational enterprise. To achieve this, he attempts to draw out from the general demands of an o…Read more
  •  13693
    The existence of evil, pain and suffering is considered by many philosophers to be the most vexed question concerning the existence of an omnipotent, omniscient and morally perfect deity. Why would a loving God permit wanton acts of cruelty and misery on the scale witnessed throughout human history? In this essay, Leslie Allan evaluates four common theistic responses to this problem, highlighting the benefits and challenges faced by each approach. He concludes with a critical examination of a th…Read more
  •  8613
    The soul-making theodicy seeks to explain how belief in the existence of God is compatible with the evil, pain and suffering we experience in our world. It purports to meet the problem of evil posed by non-theists by articulating a divine plan in which the occurrence of evil is necessary for enabling the greater good of character building of free moral agents. Many philosophers of religion have levelled strong objections against this theodicy. In this essay, Leslie Allan considers the effectiven…Read more
  •  671
    This essay explores the moral reasoning underpinning the common view that it is worse to kill a human compared with killing an animal. After examining the serious deficiencies of traditional approaches, the author develops an alternative utilitarian-based framework that proportions the seriousness of killing to levels of sentience. He demonstrates how this new approach avoids the problems faced by the application of standard utilitarian formulae in weighing the seriousness of killing many low-se…Read more
  •  684
    Some atheistic philosophers have argued that God could have created a world with free moral agents and yet absent of moral evil. Using possible world semantics, Alvin Plantinga sought to defuse this logical form of the problem of evil. In this critical note, Leslie Allan examines the adequacy of Plantinga's argument that the existence of God is logically compatible with the existence of moral evil. The veracity of Plantinga's argument turns on whether his essential use of counterfactual conditio…Read more
  •  376
    Drawing on insights from Imre Lakatos' seminal work on theories of rationality, Leslie Allan develops seven criteria for rational theory choice that avoid presuming the rationality of the scientific enterprise. He shows how his axioms of rationality follow from the general demands of an objectivist epistemology. Allan concludes by considering two weighty objections to his framework.
  •  17698
    Conservative and liberal approaches to the problem of abortion are oversimplified and deeply flawed. Accepting that the moral status of the conceptus changes during gestation, the author advances a more nuanced perspective. Through applying a form of rules in practice utilitarianism within the context of overall population policy, he provides a compelling ethical and legal framework for regulating contraception and abortion practices.
  •  1870
    The author challenges both the eliminative idealist's contention that physical objects do not exist and the phenomenalist idealist's view that statements about physical objects are translatable into statements about private mental experiences. Firstly, he details how phenomenalist translations are parasitic on the realist assumption that physical objects exist independently of experience. Secondly, the author confronts eliminative idealism head on by exposing its heuristic sterility in contrast …Read more
  •  3157
    Imre Lakatos holds a well-deserved primary place in current philosophy of science. In this essay, Leslie Allan critically examines Lakatos' theory of knowledge in two key areas. The first area of consideration is Lakatos' notion that knowledge is gained through a process of competition between rival scientific research programmes. Allan identifies and discusses four problems with Lakatos' characterization of a research programme. Next, Allan considers Lakatos' proposed test of adequacy for theor…Read more
  •  14511
    Absolutist systems of ethics have come in for harsh criticism on a number of fronts. The Principle of Double Effect was formulated by Catholic ethicists to overcome such objections. In this essay, Leslie Allan addresses four of the most prominent problems faced by an absolutist ethic and evaluates the extent to which the Principle of Double Effect is successful in avoiding or mitigating these criticisms.
  •  4011
    As a non-cognitivist analysis of moral language, Charles Stevenson's sophisticated emotivism is widely regarded by moral philosophers as a substantial improvement over its historical antecedent, radical emotivism. None the less, it has come in for its share of criticism. In this essay, Leslie Allan responds to the key philosophical objections to Stevenson's thesis, arguing that the criticisms levelled against his meta-ethical theory rest largely on a too hasty reading of his works.
  •  2756
    Leslie Allan defends his thesis that ethics is objective in the sense of requiring moral agents to offer impartial reasons for acting. Radical subjectivists have attacked this requirement for impartiality on a number of grounds. Some critics make the charge that Allan's thesis is simply a version of subjectivism in disguise. He responds by showing how a broadly naturalist view of ethics accommodates objective moral constraints. Allan also counters cases in which impartiality is purportedly not m…Read more