The Principle of Reason, the text of an important and influential lecture course that Martin Heidegger gave in 1955–56, takes as its focal point Leibniz’s principle: nothing is without reason.

Reason is precariously positioned in the Critique of Pure Reason. The Transcendental Analytic leaves no entry for reason in the cognitive process, and the Transcendental Dialectic restricts reason to noncognitive roles. Yet, in the Appendix to the Transcendental Dialectic, Kant contends that the ideas of reason can be used in empirical investigation and eventually knowledge acquisition. Given what Kant has said, how is this possible? Kant attempts to answer this in A663–A666/B691–B694 in the Appendix, where he argues that principles (...) of reason “have objective but indeterminate validity.” In Part I of this paper, I explain the full motivation behind this section. In Part II, I provide an exegesis of it. In particular, to reach his conclusion that principles of reason have objective but indeterminate validity, I interpret Kant as making three arguments from analogy. Finally, in Part III, I show that the first and third arguments fail—and what this means for Kant’s project. (shrink)

I. Immanuel Kant claims that the existence of God cannot be proved by speculative theology, yet that speculative theology is the only means by which the existence of God can definitively be proved. All knowledge, Kant argues, including that of God’s existence, must be based on the forms of possible experience or deduced from premises known to be true: in the case of the existence of God, however, the former is impossible because God transcends experience, and the latter is impossible (...) because the premises themselves, to be known to be true, would have to be grounded in possible experience, while, by the very nature of the question, possible experience has been excluded. Thus, the existence of God cannot be known in the usual sense, that is, by means of the theoretical employment of reason. (shrink)

In his 1786 essay on the pantheism controversy, ‘What Does It Mean to Orient Oneself in Thinking?’, Kant implies that ‘the maxim of reason's self-preservation [Selbsterhaltung]’ is reason's first principle for orienting itself in thinking supersensible objects. But Kant does not clearly explain what the maxim or principle of reason's self-preservation is and how it fits into his larger project of critical philosophy. Nor does the secondary literature. This article reconstructs Kant's discussion of the principle of reason's self-preservation in ‘What (...) Does It Mean to Orient Oneself in Thinking?’ It suggests that this principle is best understood as the discipline of pure reason. The principle of reason's self-preservation performs the same methodological function that Kant assigns to the discipline of pure reason. This principle establishes the rule of law in reason and subjects reason to its own laws. In so doing, it prevents reason's dialectical errors and also grounds reason's faith (Vernunftglaube), which in turn systematically conditions the practical use of reason. (shrink)

The case of John Snow has long been important to epidemiologists and public health officials. However, despite the fact that there have been many discussions about the various aspects of Snow’s case, there has been virtually no discussion about what guided Snow’s reasoning in his coming to believe his various conclusions about cholera. Here, I want to take up this question in some detail and show that there are a number of specific principles of reasoning that played (...) a crucial role for Snow. Moreover, these principles were episte- mologically important to Snow, a fact about which Snow is explicit in many places. An analysis of Snow’s case suggests that, because of the epistemic role such principles of reasoning can play, health care practitioners ought to understand their practices to be theoretically informed in these ways, and not just data driven. (shrink)

Change in View offers an entirely original approach to the philosophical study of reasoning by identifying principles of reasoning with principles for revising one's beliefs and intentions and not with principles of logic. This crucial observation leads to a number of important and interesting consequences that impinge on psychology and artificial intelligence as well as on various branches of philosophy, from epistemology to ethics and action theory. Gilbert Harman is Professor of Philosophy at Princeton University. (...) A Bradford Book. (shrink)

The subject of this article is Leibnizian interpretation of the principle of reason. Although the German philosopher called it principium grande of his philosophy, we do not find its systematic exposition in Leibniz’s works. The main aim of my paper is to present a short exposition of the principle. The article consists of three parts: in the first I present systematic exposition of the principle of reason with particular emphasis on explication of terms “principle” and “reason,” in the second, I (...) show the origins of the principle, finally, in the third part, I discuss in detail three forms of it: the principle of sufficient reason, the principle of determining reason and the principle of rendering reason. I accept two main theses: firstly, a proper interpretation of this principle requires taking into account the whole context of Leibnizian philosophy, i.e. one cannot limit oneself (as it is usually happens among researchers) to only one discipline, e.g. logic. Secondly, the ultimate methodological and heuristical foundation of the principle of reason is Leibnizian metaphysics, especially natural theology. (shrink)

This lecture course dating from 1955-56 is perhaps Heidegger's last truly important work. The book takes Leibniz's famous dictum, nihil est sine ratione--nothing is without reason--as the point of departure for a series of ruminations on the fate of modernity, modern philosophy, the atomic age, science, and the process of Seinsgeschick which is somehow responsible for our present fate of Seinsverlassenheit--abandonment by Being. Although many of these themes will be familiar to Heidegger readers from related works of the 1940s and (...) 1950s, The Principle of Reason is a significant exemplar of the later Heidegger's manner of thinking and philosophical concerns. (shrink)

I have been supposing that for the theory of reasoning, explicit belief is an all-or-nothing matter, I have assumed that, as far as principles of reasoning are concerned, one either believes something explicitly or one does not; in other words an appropriate "representation" is either in one's "memory" or not. The principles of reasoning are principles for modifying such all-or-nothing representations. This is not to deny that in some ways belief is a matter of (...) degree. For one thing implicit belief is certainly a matter of degree, since it is a matter of how easily and automatically one can infer something from what one believes explicitly. Furthermore, explicit belief is a matter of degree in the sense that one believes some things more strongly than others. Sometimes one is only somewhat inclined to believe something, sometimes one is not sure what to believe, sometimes one is inclined to disbelieve something, sometimes one is quite confident something is not so, and so forth. (shrink)

In the Transcendental Dialectic of the first Critique, Kant famously claims that even if ideas and principles of reason cannot count as cognitions of objects, they can play a positive role when they are used “regulatively” with the aim of organizing our empirical cognitions. One issue is to understand what assuming “regulatively” means. What kind of attitude does this “assuming” imply? Another issue is to characterize the status of ideas and principles themselves. It is to this second issue (...) that this article is dedicated. Some interpreters have suggested that ideas and principles that can be assumed regulatively consist of propositions that we know are false. Others have suggested that at least some regulative ideas, as for example the idea of the homogeneity of nature, consist of propositions that we know are true but are indeterminate. Still others argue that, in assuming regulative ideas and principles, we assume propositions that cannot be proved true, but are nonetheless possibly true. In this article, I reject the view that regulative ideas consist of true but indeterminate propositions. Moreover, I argue that it is wrong to presuppose that only one of the remaining two options can apply to Kant’s account of regulative ideas and principles. By contrast, I submit that while in some cases assuming regulative ideas and principles does involve assuming some propositions that we know are false, this is not true for all regulative ideas and principles. More specifically, assuming regulative ideas involves assuming false propositions when assuming them means assuming that a “totality of appearances” is given. (shrink)

The principle of right is Kant's main formulation of the rules of politics, and it has obvious affinities with the moral law. Do we have moral reasons to obey the principle? I argue that we may have moral reasons to obey the principle ourselves, but not coercively to enforce it. Do we have prudential reasons to obey the principle? I argue that we do not have reasons based on happiness, but that we may have prudential reasons of a wholly different, (...) but distinctively Kantian kind. These may be reasons both to obey the principle ourselves and to enforce it. (shrink)

I distinguish three ways in which early modern rationalists seek to apply the principle of sufficient reason to empirical science, and critically assess some of their attempts to do so. I focus especially on how these thinkers assume substantive theories of explanation and intelligibility--which are indebted to the mechanist and experimentalist traditions--in many of their deployments of this rationalist principle. A recurring problem is that these philosophers deploy their standards of intelligibility inconsistently: some of their own favored explanations do not (...) always live up to their standards. I argue that the problem is especially acute for Leibniz and Euler, given their enthusiasm for final-causal explanations. (shrink)

The Principle of Sufficient Reason is a powerful and controversial philosophical principle stipulating that everything must have a reason or cause. This simple demand for thoroughgoing intelligibility yields some of the boldest and most challenging theses in the history of metaphysics and epistemology. In this entry we begin with explaining the Principle, and then turn to the history of the debates around it. A section on recent discussions of the Principle will be added in the near future.

A guide to developing logical thought and expression through discussion and exercises.

According to the Principle of Sufficient Reason (henceforth ‘PSR’), everything has an explanation or sufficient reason. This paper addresses three questions. First, how continuous is the contemporary notion of grounding with the notion of sufficient reason endorsed by Spinoza, Leibniz, and other rationalists? In particular, does a PSR formulated in terms of ground retain the intuitive pull and power of the PSR endorsed by the rationalists? Second, to what extent can the PSR avoid the formidable traditional objections levelled against it (...) if it is formulated in terms of ground? And finally, how might historical discussion of the PSR shed light on the contemporary notion of grounding? (shrink)

A textbook for undergraduate, introductory logic and critical thinking courses, Principles of Logic and Reasoning: Including LSAT, GRE, and Writing Skills by Christine A. James meets a specific set of student needs. The text is engaging and readable, but also includes detailed terms, definitions, section headings, and short exercises that build a specific set of foundational logic and argumentation skills. Each key term is carefully indexed in the back of the text so that students can review easily. The (...) text includes chapters that show how logic and reasoning can be used in planning major research papers, and how logic and argumentation connects with legal reasoning and preparing for graduate level examinations that have analytic reasoning sections such as the GRE and LSAT. Often logic textbooks do not include sections on issues like these that show the relevance of logic for the average college student. This textbook is unique because it leaves students with a clear understanding that they can and will use logic to their advantage beyond their first logic course. Another advantage of this text for students is the low cost, some logic textbooks are triple the cost of this textbook. -/- For faculty members, this text has advantages as well. Each section has an exercise that is clear, concise, and adaptable to online course platforms and frequently used lecture tools like PowerPoint and Prezi. With seven chapters, the book is suited for courses that are taught in sessions of varying weeks. Many schools now offer classes in formats of 8 weeks, 10 weeks, or 16 weeks. This text is arranged with a number of chapters that can be covered in any weekly format, with sections that can be included or not included at the discretion of the instructor. Written by a faculty member at a regional state university with an emphasis on accessible undergraduate teaching, the text is written in a relaxed, conversational style so that students from diverse backgrounds will feel comfortable with the examples used. The book welcomes students to continue studying Logic in other more advanced courses. Topics covered include essential approaches to critical thinking, informal logic, fallacies, categorical logic, Venn diagrams, formal symbolic logic, first order rules of inference and replacement, as well as logic in writing and preparing for graduate school and law school. (shrink)

The principle of insufficient reason is one of those philosophic concepts that are highly symptomatic concerning the ultimate presuppositions of the person who accepts them as fundamental. This principle asserts that where we do not have sufficient reason to regard one possible case as more probable than another, we may treat them as equally probable. It has been violently rejected by various logicians, asserted to produce absurdities, and yet has remained persuasively attractive, being accepted, for example, by such an outstanding (...) logician as Dotterer. It may hence be worth while to inquire what the acceptance of this principle implies and what is the source of its persuasiveness. (shrink)

The Principle of Sufficient Reason says that all contingent facts must have explanation. In this 2006 volume, which was the first on the topic in the English language in nearly half a century, Alexander Pruss examines the substantive philosophical issues raised by the Principle Reason. Discussing various forms of the PSR and selected historical episodes, from Parmenides, Leibnez, and Hume, Pruss defends the claim that every true contingent proposition must have an explanation against major objections, including Hume's imaginability argument and (...) Peter van Inwagen's argument that the PSR entails modal fatalism. Pruss also provides a number of positive arguments for the PSR, based on considerations as different as the metaphysics of existence, counterfactuals and modality, negative explanations, and the everyday applicability of the PSR. Moreover, Pruss shows how the PSR would advance the discussion in a number of disparate fields, including meta-ethics and the philosophy of mathematics. (shrink)

The Principle of Sufficient Reason is very seldom, if ever, referred to in the works of whom we might think of as the eminent Asian metaphysicians. In spite of this, the big picture metaphysical views available in the thought of philosophers such as Nāgārjuna, Fazang and Nishida appear to share certain structural features with views more familiar to us from our own tradition; views that explicitly accept or reject the Principle of Sufficient Reason. Nāgārjuna looks to develop a kind of (...) metaphysical infinitism, Fazang an extreme form of coherentism, and Nishida a species of foundationalism. These three positions - infinitism, coherentism and foundationalism - are typically thought to exhaust the spread of possibilities by those working within the Western tradition. -/- In spite of their similarities to positions advanced within our own tradition, the cosmologies of many of the giants of Asian philosophy are characterised by their rather striking conclusions. Amongst such conclusions for Nāgārjuna is that everything is empty; for Fazang that everything is identical to everything else; and for Nishida that everything depends on absolute nothingness. If the Principle of Sufficient Reason is playing a role in the derivation of such striking conclusions, then it looks that there are more options regarding the metaphysical structure of the world available to us than our own tradition typically courts. If, on the other hand, these striking cosmological conclusions are arrived at without any consideration of sufficient reason, then there may well be ways of reasoning about the overarching structure of reality that are powerful but unfamiliar to Western thinking. In this contribution, I explore what, if any, role the PSR might be playing in the thought of Nāgārjuna , Fazang and Nishida, and what we might be able to learn from it. (shrink)

Since 2011, the focus of international negotiations under the UNFCCC has been on producing a new climate agreement to be adopted in 2015. This phase of negotiations is known as the Durban Platform for Enhanced Action. The goal has been to update the global effort on climate for long-term cooperation. In this period, various changes have been contemplated on the design of the architecture of the global climate effort. Whereas previously, the negotiation process consisted of setting mandated targets exclusively for (...) developed countries, the current setting requests of each country to pledge its contribution to the climate effort in the form of Intended Nationally Determined Contributions. The shift away from establishing negotiated targets for rich countries alone towards a universal system of participation through intended contributions raised persistent questions on how exactly the new agreement can ensure equitable terms. How to conceptualize equity within the 2015 climate agreement, and beyond, is the focus of this paper. The paper advances a framework on equity, which moves away from substantive moral conceptions of burden allocation toward refining principles of public reason specially designed for the negotiation process under the UNFCCC. The paper outlines the framework’s main features and discusses how it can serve a facilitating role for multilateral discussion on equity on a long-term basis capable of adapting to changing circumstances. (shrink)

The right to ‘domestic remedies’, which ideally connects ‘subsidiarity’ and ‘embeddedness’ of the ECHR in the legal systems of member States, is deemed to play a crucial role for the Strasbourg machinery survival as well as for an effective protection of human rights, especially in the field of the ‘reasonable-time’ requirement. In this respect the Italian case seems an excellent test. Once a compensatory remedy was introduced in the Italian legal system by Law No. 80 of 2001 (the ‘Pinto Act’), (...) it soon appeared that such a remedy could be considered ‘effective’ in so far as it was implemented in accordance with the ECtHR’s jurisprudence. Therefore a legal tool for the interaction between ECtHR and Italian courts had to be found. Nevertheless, the results of this interaction might suggest that the domestic remedy has neither increased the protection of the reasonable-time requirement in Italy nor is it the final solution to the ECtHR’s overload. (shrink)

Leibniz was a philosopher of principles: the principles of Contradiction, of Sufficient Reason, of Identity of Indiscernibles, of Plenitude, of the Best, and of Continuity are among the most famous Leibnizian principles. In this article I shall focus on the first three principles; I shall discuss various formulations of the principles (sect. 1), what it means for these theses to have the status of principles or axioms in Leibniz’s philosophy (sect. 2), the fundamental character (...) of the Principles of Contradiction and Sufficient Reason (sect. 3), some attempts to demonstrate the Principles of Contradiction and Sufficient Reason (sect. 4), and one attempt to demonstrate the Principle of Identity of Indiscernibles (sect. 5). The main results of the chapter are summarized in a short conclusion (sect. 6). (shrink)

Toward the end of his classic treatise An Essay on Free Will, Peter van Inwagen offers a modal argument against the Principle of Sufficient Reason which he argues shows that the principle “collapses all modal distinctions.” In this paper, a critical flaw in this argument is shown to lie in van Inwagen’s beginning assumption that there is such a thing as the conjunction of all contingently true propositions. This is shown to follow from Cantor’s theorem and a property of conjunction (...) with respect to contingent propositions. Given the failure of this assumption, van Inwagen’s argument against the Principle of Sufficient Reason cannot succeed, at least not without the addition of some remarkable and previously unacknowledged qualifications. (shrink)

Alexander Pruss’s Principle of Sufficient Reason states that every contingent true proposition has an explanation. Pruss thinks that he can plausibly maintain both his PSR and his account of libertarian free will. This is because his libertarianism has it that contingent true propositions reporting free choices are self-explanatory. But I don’t think Pruss can plausibly maintain both his PSR and libertarianism without a rift occurring in one or the other. Similar to the old luck/randomness objection, I contend that Pruss’s libertarianism (...) is susceptible to what I call “the inexplicability objection”, which attempts to show that agents’ free choices involve contingent brute facts. Pruss may be able to partially explain a proposition such that Jones freely chose A for reason R, but he cannot adequately explain a contrastive proposition such as that Jones freely chose A for R rather than B for R*. The result is that either PSR is too explanatorily permissive for libertarianism, or libertarianism is too explanatorily impermissive to satisfy PSR. After considering what I take to be Pruss’s best response to the inexplicability objection, I conclude that his attempt to reconcile PSR and libertarianism is unsuccessful. (shrink)

Kant's attack on metaphysics consists in large part in his attack on a principle that he names the Supreme Principle of Pure Reason. This principle, it is not often noticed, is the Principle of Sufficient Reason [PSR]. In interpreting this principle as such, I argue that Kant's attack on the PSR depends on Kant's claim that existence is not a first-order predicate. If existence isn't what Kant calls a real predicate, the PSR is false. While this constitutes a powerful Kantian (...) argument against dogmatic rationalism, it also poses a problem for Kant. For, as I argue, if the PSR is true, Kant's argument that existence isn't a first-order predicate is false. In this sense, Kant's attack on the PSR is begging the question vis-á-vis radical metaphysicians. Concluding the paper I suggest relying on Kant's 'is'/'ought' distinction in avoiding this circularity, thereby reinforcing the Kantian critique. (shrink)

Leibniz, and many following him, saw the Principle of Sufficient Reason (PSR) as pivotal to a scientific (demonstrated) metaphysics. Against this backdrop, Kant is expected to pay close attention to PSR in his reflections on the possibility of metaphysics, which is his chief concern in the Critique of Pure Reason. It is far from clear, however, what has become of PSR in the Critique. On one reading, Kant has simply turned it into the causal principle of the Second Analogy. On (...) a different reading, PSR is but the supreme principle of reason, which roughly states that, if the conditioned is given, so is the unconditioned. On my reading, PSR appears in the guises of both the causal principle and the supreme principle. This twofold specification, I argue, is key to understanding (i) Kant’s allegations that past metaphysicians failed to prove PSR, (ii) his own Critical account of the possibility of metaphysics in both of its parts (ontology and metaphysics proper), and (iii) his nuanced answer to the contentious question about the relation between physical inquiry and metaphysical reasoning about nature (both being quests for reasons). (shrink)