This article develops an interpretation and defense of Husserl’s account of the omnitemporality of idealities. I first examine why Husserl rejects the atemporality and temporal individuation of idealities on phenomenological grounds, specifically that these attributions prove countersensical in how they relate idealities to consciousness. As an alternative to these conceptions, I develop a two-sided interpretation of omnitemporality expressed in modal terms of actuality and possibility, the actual referring to appearances in time and the possible, to reactivation at any time. In (...) defense of this interpretation of omnitemporality, I consider influential criticisms against Husserl’s account of idealities as they concern time, particularly whether the historical genesis of idealities compromises their omnitemporality by binding them to time. Ultimately, I argue that the transcendental historicity of idealities, despite being relevant to the question of validity and access, proves indifferent to their omnitemporality. (shrink)

In this paper I will show that the omnitemporality of truth does indeed imply fatalism if the past is unchangeable. I then argue that it is very likely indeed that the past is unchangeable and thus, since it is very likely that fatalism is false, it is very likely that the doctrine of the omnitemporality of truth is false. I argue that the rejection of the omnitemporality of truth has no undesirable consequences for either logic or theology, that in fact (...) the logical and theological consequences of the rejection of the omnitemporality of truth are beneficial to both disciplines. (shrink)

Shows that a certain temporal logic has infinitely many non-equivalent formulae in a single variable.

The paper purports to show that truth-atemporalism, the thesis that truth is timeless, is incompatible with power to do otherwise. Since a parallel and simpler argument can be run to the effect that truth-omnitemporalism, the thesis that truth is sempiternal, is incompatible with power to do otherwise, our conclusion achieves greater generality, and the possible shift from the claim that truth is omnitemporal to the claim that it is atemporal becomes useless for the purpose to resist it. On the (...) other hand, our argument for the conclusion that both Atemporalism and Omnitemporalism are incompatible with power to do otherwise will be shown independent of the debated assumption that the past is inalterable. So our argument goes through independently of whether Ockhamists are right in insisting that the soft facts about the past are alterable. (shrink)

The past six decades have seen rising interest in the philosophy of time, driven in large measure by the metaphysical implications of the physical theories of relativity and quantum mechanics. Philosophical theology has only recently begun serious interaction with contemporary metaphysics of time. In particular, the issue of God's temporal mode of being has come under investigation In Part 1, I begin with the metaphysics of time, explicating and defending a causal account of dynamic time. I then consider objections that (...) can be brought against this account from the standpoint of the Special and General Theories of Relativity and Quantum Mechanics, and conclude that one of the objections are compelling. In Part II, I consider the evidence from Scripture relative to God's temporal mode of being, and find that it is neutral between a temporal and an atemporal conception. The arguments upholding the medieval consensus in philosophical theology of divine timelessness are evaluated, along with contemporary arguments for atemporality. Openness to divine temporality is discernible in some medieval philosophers; their arguments, along with contemporary arguments for temporality, are investigated. I then offer an analysis of the concept of omnitemporality which I take to be the form of temporality most appropriate to expressing God's temporal mode of being. Finally I argue that objections to omnitemporality are not forceful, and that the concept has in its favor greater explanatory power for a range of issues in philosophical theology. (shrink)

God is thought to be eternal. Does this mean that he is timeless? Or is he, rather, omnitemporal? In this paper we want to show that God cannot be omnitemporal. Our starting point, which we take from Bernard Williams’ article on the Makropulos Case, is the intuition that it is inappropriate for persons not to become bored after a sufficiently long sequence of time has passed. If God were omnitemporal, he would suffer from boredom. But God is the greatest possible (...) being and therefore cannot be bored. God, hence, is not omnitemporal. After the presentation of our argument, we address several objections by examining possible differences between human and divine persons. (shrink)

The word "modem" in the title of this book refers primarily to post-medieval discussions, but it also hints at those medieval mo dal theories which were considered modem in contradistinction to ancient conceptions and which in different ways influenced philosophical discussions during the early modem period. The me dieval developments are investigated in the opening paper, 'The Foundations of Modality and Conceivability in Descartes and His Predecessors', by Lilli Alanen and Simo Knuuttila. Boethius's works from the early sixth century belonged (...) to the sources from which early medieval thinkers obtained their knowledge of ancient thought. They offered extensive discus sions of traditional modal conceptions the basic forms of which were: (1) the paradigm of possibility as a potency striving to realize itself; (2) the "statistical" interpretation of modal no tions where necessity means actuality in all relevant cases or omnitemporal actuality, possibility means actuality in some rel evant cases or sometimes, and impossibility means omnitemporal non-actuality; and (3) the "logical" definition of possibility as something which, being assumed, results in nothing contradic tory. Boethius accepted the Aristotelian view according to which total possibilities in the first sense must prove their met tle through actualization and possibilities in the third sense are assumed to be realized in our actual history. On these presump tions, all of the above-mentioned ancient paradigms imply the Principle of Plenitude according to which no genuine possibility remains unrealized. (shrink)

Take open-future Humeanism to comprise the following four tenets: (T1) that truth supervenes on a mosaic of local particular matters of fact; (T2) that there are no necessary connections between distinct existences; (T3) that there is a dynamic present moment; and (T4) that there are no future facts; that is, contingent propositions about the future obtain truth values only when their referents are actualised. Prima facie this is a deeply problematic metaphysic for the Humean, since given that the widely accepted (...) Humean conception takes all truths (inclusive of nomological truths) to supervene on an omnitemporal mosaic of local particular matters of fact, if there are no future facts, then the Humean can neither provide laws of nature, nor justify many everyday inductive inferences. However, I argue that this eternalist metaphysic is in tension with at least one of Hume’s central metaphysical claims concerning causation, e.g. that causal regularities may cease to hold at any time. In this paper I propose and defend one possible open-future Humean metaphysic which admits of “true-to-Hume” causal and nomological facts. Furthermore, although I am happy to concede that induction is problematic for the open-future Humean, I demonstrate that it poses no greater threat to the open-future conception than it does to the popular Lewisian conception of natural law. (shrink)

I argue that the following two claims provide us with sufficiently strong reason to conclude that God came into existence from nothing a finite time in the past: that God is omnitemporal; and that there is a first moment of time. After defending the possibility of God beginning to exist ex nihilo from various objections, I critique two alternative attempts at providing an account of the relationship between an omnitemporal God and the beginning of time. I show that these either (...) fail to be an alternative to my own model or are less supported by the relevant evidence. (shrink)

Le but de l'article est de cerner le sens précis du concept de constitution, central dans la pensée de Husserl, et ce afin de comprendre la portée ontologique de son idéalisme transcendantal: en quel sens s'agit-il d'un idéalisme? Le sujet constituant produit-il le sens et l'être des objets? On s'interroge d'abord sur le champ d'objets qui sert à Husserl de fil conducteur pour l'élaboration de ce concept: est-ce celui des objets immanents, des choses spatio-temporelles, ou des idéalités? Ayant montré que (...) la constitution de la res extensa possède une fonction paradigmatique, on met en question la possibilité de transposer ses traits essentiels à celle des idéalités formelles ou mathématiques: celles-ci ont-elles une subsistance et un caractère d'Idée kantienne analogues à ceux de la res extensa? Comment concilier leur validité omnitemporelle, qui accrédite une thèse réaliste, et le fait qu'elles apparaissent à un moment précis de l'histoire, qui semble justifier la thèse idéaliste? The aim of this article is to tackle and define the concept of constitution, which is central in Husserl's thought, in order to understand the ontological significance of its transcendental idealism: what kind of idealism is it? Does the constituting subject produce the sense and the being of objects? The first question will be to know what field of objects Husserl uses as paradigm in the construction of this concept: is it the field od immanent temporal objects, of spatiotemporal things or of idealities? Having proved that the constitution of the res extensa has a paradigmatic fonction, is it possible to transfer its main characteristics to the constitution of formal or mathematical idealities? Do the latter have the same subsistence and the same statut of Kantian ideas as the res extensa? How is possible to reconcile their omnitemporal validity with the fact that they appear at a particular time in history? (shrink)

A difficulty for a view of divine eternity as timelessness is that if time is tensed, then God, in virtue of His omniscience, must know tensed facts. But tensed facts, such as It is now t, can only be known by a temporally located being.Defenders of divine atemporality may attempt to escape the force of this argument by contending either that a timeless being can know tensed facts or else that ignorance of tensed facts is compatible with divine omniscience. Kvanvig, (...) Wierenga, and Leftow adopt both of these strategies in their various defenses of divine timelessness. Their respective solutions are analyzed in detail and shown to be untenable.Thus, if the theist holds to a tensed view of time, he should construe divine eternity in terms of omnitemporality. (shrink)

In this paper I shall look at the application of the ltration technique to omnitemporal logic . The principal result of the paper will be that the system BSeg of [3] has the nite model property; but I shall also make a few remarks about the system B+ of [2].

Take strong open-future Humeanism (OFH) to comprise the following three tenets: (i) that truth supervenes on being (ii) that there is a dynamic present moment, and (iii) that there are no future facts; that is, contingent propositions about the future obtain truth values only when their referents are actualised (Tooley 1997). On the face of it this is a deeply problematic metaphysic - if there are no future facts then prima facie the Humean can neither provide laws of nature, nor (...) explain the evolution of physical systems, as the Humean takes truths (including nomological truths) to supervene on the omnitemporal mosaic of local particular matters of fact. Hypertemporal Humeanism (HH), the view I propose in this paper, admits of nomological facts whilst granting the ontological and conceptual commitments of OFH. HH provides a coherent account of laws of nature, and (unlike standard Humean conceptions) accommodates the natural intuition that future facts are yet to be determined. Furthermore, although the view arguably struggles to combat the problem of induction, the Hypertemporal Humean is in no worse a position in this respect than the traditional closed-future Humean metaphysics. (shrink)

This paper specifies classes of framesmaximally omnitemporally characteristic for Thomas' normal modal logicT 2 + and for each logic in the ascending chain of Segerberg logics investigated by Segerberg and Hughes and Cresswell. It is shown that distinct a,scending chains of generalized Segerberg logics can be constructed from eachT n + logic (n 2). The set containing allT n + and Segerberg logics can be totally- (linearly-) ordered but not well-ordered by the inclusion relation. The order type of this ordered (...) set is *( + 1). Throughout the paper my approach is fundamentally semantical. (shrink)

This dissertation is concerned with one of the central but most perplexing theories in Plotinus's metaphysics, namely the nature and origin of time. In contrast to those interpretations of Neoplatonism that treat time as an imperfect image and passive product of eternity, I argue for a much more subtle and multifaceted concept that makes the human observer central to Plotinus's account of how time is actualized and thus passes. His emphasis on mystical experience and the individual soul's journey toward the (...) One and the realm of eternity strengthens this account. By reading the treatise On Eternity and Time in this light, I demonstrate the importance of embodied human consciousness for the Plotinian theory of time. ;This emphasis invites comparison with the one contemporary Continental thinker who devoted countless pages in both his published work and his manuscripts to the relationship between time and consciousness. In the second part of the dissertation I argue that the Husserlian and Plotinian subjects have analogous characteristics, in accordance with their parallel roles as sources of time, and that the Husserlian notion of omnitemporality offers the best way of understanding the internal connection between Plotinus's notion of eternity and his notion of actualization through human experience. At the same time, Plotinus challenges a phenomenological account by giving the eternal ontological priority over the human realm of temporality. Nevertheless, these intriguing affinities and oppositions suggest that Plotinus's theory of time and eternity can best be understood and even expanded by uncovering its phenomenological underpinnings. (shrink)

Not much attention has been paid to Malebranche’s philosophy of time. Scholars who have written on it have typically written about it only in passing, and by and large discuss it only in relation to his philosophy of religion. This is appropriate insofar as Malebranche doesn’t discuss his views of time in isolation from his religious metaphysics. I argue that Malebranche’s conception of how created beings have their properties commits him to saying that God is omnitemporal rather than atemporal. For (...) just as bodies get their spatiality by participating in God’s omnipresence, so all creatures get their temporality by participating in God’s omnitemporality. Moreover, Malebranche is a substantivalist about space and time: infinite space and time are one and the same divinely simple substance, God (partially considered), who contains the world. My exploration of Malebranche’s metaphysics sheds light on his views of eminent containment, participation, and causation. (shrink)

The paper discusses this year’s Nobel Prize in physics for experiments of entanglement “establishing the violation of Bell inequalities and pioneering quantum information science” in a much wider, including philosophical context legitimizing by the authority of the Nobel Prize a new scientific area out of “classical” quantum mechanics relevant to Pauli’s “particle” paradigm of energy conservation and thus to the Standard model obeying it. One justifies the eventual future theory of quantum gravitation as belonging to the newly established quantum information (...) science. Entanglement, involving non-Hermitian operators for its rigorous description, non-unitarity as well as nonlocal and superluminal physical signals “spookily” (by Einstein’s flowery epithet) synchronizing and transferring some nonzero action at a distance, can be considered to be quantum gravity so that its local counterpart to be Einstein’s gravitation according to general relativity therefore pioneering an alternative pathway to quantum gravitation different from the “secondary quantization” of the Standard model. So, the experiments of entanglement once they have been awarded by the Nobel Prize launch particularly the relevant theory of quantum gravitation grounded on “quantum information science” thus granted to be nonclassical quantum mechanics in the shared framework of the generalized quantum mechanics obeying rather quantum-information conservation than only energy conservation. The concept of “dark phase” of the universe naturally linked to the very well confirmed “dark matter” and “dark energy” and opposed to its “light phase” inherent to classical quantum mechanics and the Standard model obeys quantum-information conservation, after which reversible causality or the mutual transformation of energy and information are valid. The mythical Big Bang after which energy conservation holds universally is to be replaced by an omnipresent and omnitemporal medium of decoherence of the dark and nonlocal phase into the light and local phase. The former is only an integral image of the latter and borrowed in fact rather from religion than from science. Physical, methodological and proper philosophical conclusions follow from that paradigm shift heralded by this year’s Nobel Prize in physics. For example, the scientific theory of thinking should originate from the dark phase of the universe, as well: probably only approximately modeled by neural networks physically belonging to the light phase thoroughly. A few crucial philosophical sequences follow from the break of Pauli’s paradigm: (1) the establishment of the “dark” phase of the universe as opposed to its “light” phase, only to which the Cartesian dichotomy of “body” and “mind” is valid; (2) quantum information conservation as relevant to the dark phase, furthermore generalizing energy conservation as to its light phase, productively allowing for physical entities to appear “ex nihilo”, i.e., from the dark phase, in which energy and time are yet inseparable from each other; (3) reversible causality as inherent to the dark phase; (4) the interpretation of gravitation only mathematically: as an interpretation of the incompleteness of finiteness to infinity, for example, following the Gödel dichotomy (“either contradiction or incompleteness”) about the relation of arithmetic to set theory; (5) the restriction of the concept of hierarchy only to the light phase; (6) the commensurability of both physical extremes of a quantum and the universe as a whole in the dark phase obeying quantum information conservation and akin to Nicholas of Cusa’s philosophical and theological worldview. (shrink)

Gravitation is interpreted to be an “ontomathematical” force or interaction rather than an only physical one. That approach restores Newton’s original design of universal gravitation in the framework of “The Mathematical Principles of Natural Philosophy”, which allows for Einstein’s special and general relativity to be also reinterpreted ontomathematically. The entanglement theory of quantum gravitation is inherently involved also ontomathematically by virtue of the consideration of the qubit Hilbert space after entanglement as the Fourier counterpart of pseudo-Riemannian space. Gravitation can be (...) also interpreted as purely mathematical or logical “force” or “interaction” as a corollary from its ontomathematical (rather than physical) realization. The ontomathematical approach to gravitation is implicit in general relativity equating it to operators in pseudo-Riemannian space obeying the Einstein field equation and also well-known by the “geometrization of physics”. Quantum mechanics shares the same by the separable complex Hilbert space and defining “physical quantity” by the Hermitian operators on it. One can interpret special Minkowski space involved by special relativity and the qubit Hilbert space of quantum information as Fourier counterparts immediately noticing that general relativity means gravitation as the Fourier counterpart of non-Hermitian operators implying non-unitarity and the violation of energy conservation and thus destroying Pauli’s particle paradigm. Since the Standard model obeys it, this explains the impossibility of “quantum gravitation” in any framework conservatively generalizing the Standard model so that it would include gravitation along with electromagnetic, weak, and strong interactions. Einstein’s geometrization of gravitation can be continued into a purely mathematical theory of it following Euclid’s realization for geometry to be exhaustively built in a deductive and axiomatic way as well as Riemann’s parametrization of all the class of Euclidean and non-Euclidean geometries by “space curvature”, then being generalized to Minkowski space as the operators on pseudo-Riemannian space as the Einstein field equation means gravitation. The transition from mathematical gravitation to logical one can rely on the historical lesson of the pair of Lobachevski’s and Riemann’s approaches now “reversely”, i.e., from the latter to the former. Logical gravitation is linkable to Hegel’s dialectical logic and ontological dialectics abandoning their interpretations as a new zero logic substituting classical propionyl logic. The approach of ontomathematics generalizing that of ontology, traceable even to Aristotle’s reformation of Plato’s doctrine, needs Hegel’s doctrine to be formalized as a first-order logic naturally containing Boolean algebra, isomorphic to both classical propositional logic and set theory being the class of all first-order logics, as a sub-logic along with Peano arithmetic as another sub-logic. The first-order logic at issue is called Hilbert arithmetic and elaborated in detail in other papers. It allows for both self-foundation of mathematics to be internally proved as complete and furthermore, quantum mechanics reinterpreted as quantum information to be included by the qubit Hilbert space interpretable in turn as a dual and physical counterpart of Hilbert arithmetic in a narrow sense, that is, both counterparts constitute Hilbert arithmetic in a wide sense, being mathematical and physical simultaneously and thus overcoming the Cartesian dualism of “body” gapped from “mind” by an abyss. Then, the proper philosophical interpretation of gravitation to be the fundamental ontomathematical force or interaction overcomes the ridiculous belief of the Big Bang wrongly alleged to be a scientific theory. Ontomathematical gravitation suggests an omnipresent and omnitemporal medium of “God’s” creation “ex nihilo” following only the natural necessity of quantum-information conservation particularly and locally manifested as energy conservation. (shrink)

The paper discusses Hilbert mathematics, a kind of Pythagorean mathematics, to which the physical world is a particular case. The parameter of the “distance between finiteness and infinity” is crucial. Any nonzero finite value of it features the particular case in the frameworks of Hilbert mathematics where the physical world appears “ex nihilo” by virtue of an only mathematical necessity or quantum information conservation physically. One does not need the mythical Big Bang which serves to concentrate all the violations of (...) energy conservation in a “safe”, maximally remote point in the alleged “beginning of the universe”. On the contrary, an omnipresent and omnitemporal medium obeying quantum information conservation rather than energy conservation permanently generates action and thus the physical world. The utilization of that creation “ex nihilo” is accessible to humankind, at least theoretically, as long as one observes the physical laws, which admit it in their new and wider generalization. One can oppose Hilbert mathematics to Gödel mathematics, which can be identified as all the standard mathematics until now featureable by the Gödel dichotomy of arithmetic to set theory: and then, “dialectic”, “intuitionistic”, and “Gödelian” mathematics within the former, according to a negative, positive, or zero value of the distance between finiteness and infinity. A mapping of Hilbert mathematics into pseudo-Riemannian space corresponds, therefore allowing for gravitation to be interpreted purely mathematically and ontologically in a Pythagorean sense. Information and quantum information can be involved in the foundations of mathematics and linked to the axiom of choice or alternatively, to the field of all rational numbers, from which the pair of both dual and anti-isometric Peano arithmetics featuring Hilbert arithmetic are immediately inferable. Noether’s theorems (1918) imply quantum information conservation as the maximally possible generalization of the pair of the conservation of a physical quantity and the corresponding Lie group of its conjugate. Hilbert mathematics can be interpreted from their viewpoint also after an algebraic generalization of them. Following the ideas of Noether’s theorem (1918), locality and nonlocality can be realized both physically and mathematically. The “light phase of the universe” can be linked to the gap of mathematics and physics in the Cartesian organization of cognition in Modernity and then opposed to its “dark phase”, in which physics and mathematics are merged. All physical quantities can be deduced from only mathematical premises by the mediation of the most fundamental physical constants such as the speed of light in a vacuum, the Planck and gravitational constants once they have been interpreted by the relation of locality and nonlocality. (shrink)

In this essay, I consider some logical treatises and commentaries from the first decades of the 12th century (many of which are still unedited) which contain a discussion on modalities and modal logic. After presenting a short catalogue of these sources and a description of their common features, I shall focus on some definitions of the modal term “necessarium” which are provided in them. As we will see, Abelard and logicians of his time advanced three different characterizations of this term: (...) necessity was either defined in terms of unavoidability (ineuitabilitas), or in terms of immutability and omnitemporality (impermutabilitas, sempiternitas), or again in terms of absolute necessity as opposed to conditioned one (necessitas absoluta vs. determinata). I argue that the temporal understanding of necessity in terms of omnitemporality, inherited from ancient sources and extensively used by Abelard and others in the first years of the twelfth-century, started to disappear in texts datable from around the 1120, perhaps due to several difficulties that were related to this definition when applied in logical contexts. I also discuss how the notion of necessitas determinata was used by Abelard’s contemporaries to qualify the modal status of present and past events, which were generally believed to be necessary only in a “weak” and harmless sense that did not prevent them from being contingent. -/- . (shrink)

This book summarizes the intense research that the author performed for his Ph.D. thesis , revised and with the addition of an intuitionistic critique of Husserl's concept of number. His starting point consisted of a double conviction: 1) Brouwerian intuitionism is a valid way of doing mathematics but is grounded on a weak philosophy; 2) Husserlian phenomenology can provide a suitable philosophical ground for intuitionism. In order to let intuitionism and phenomenology match, he had to solve in general two problems: (...) 1) the question of the reciprocal indifference that the authors had toward each other's theorizing which indeed they knew; 2) Husserl's general attitude of accepting classical mathematics, which contrasts with the critical attitude of the intuitionists.Moreover, in the specific case focused on by this book—concerning choice sequences, that is, sequences that can be completely lawless and that were admitted as mathematical entities by Brouwer—van Atten had to handle a further problem: such sequences do not fit the characteristic of omnitemporality that the late Husserl seemed to consider a necessary attribute of entities if they were to be considered mathematical. In as far as they are lawless we cannot predict at any moment how they will develop in the future, hence they are not determined at any particular time—they will be determined only in the future.Let us begin with van Atten's first conviction, i.e., that Brouwerian intuitionism is grounded on a weak philosophy. We have to recall that Brouwer provided a mystical attitude for proposing his intuitionism: man can obtain happiness only by keeping himself closed inside the inner Self. Any attempted movement towards the exterior world is a source of pain: in particular language and the sciences. Mathematics, in order to be morally acceptable …. (shrink)

Unlike versions of open theism that appeal to the alethic openness of the future, defenders of limited foreknowledge open theism (hereafter LFOT) affirm that some propositions concerning future contingents are presently true. Thus, there exist truths that are unknown to God, so God is not omniscient simpliciter. LFOT requires modal definitions of divine omniscience such that God knows all truths that are logically knowable. Defenders of LFOT have yet to provide an adequate response to Richard Purtill’s argument that fatalism logically (...) follows from the omnitemporality of truth. Hasker believes a distinction between hard and soft facts prevents fatalism, but I argue that his defense fails in light of arguments involving divine necessity. Additionally, I point out that Hasker’s philosophy of language concerning divine names faces problems that cannot be overcome, given the versions of the dilemma of freedom and foreknowledge that motivate LFOT. Thus, contra Hasker, Swinburne, and van Inwagen, open theism necessitates the alethic openness of the future. (shrink)

The central aim of this short and pithy book is to challenge the widely held view that the concepts expressed by Aristotelian modal idioms are essentially temporal modalities, by which is meant that they can be defined wholly by means of non-modal and temporal idioms. More specifically, Waterlow contends that two notorious Aristotelian theses, if it is possible that p, then at some time it is the case that p, and if it is always the case that p, then it (...) is necessary that p, are not to be understood, even in restricted forms, as analytic outfall of the very nature of Aristotle's modalities. Rather, she argues, they are viewed by Aristotle himself as substantive principles whose truth he undertakes to establish in De Caelo 1.12 by means of an assortment of premises, some of which do flow from the nature of the modalities involved, but others of which pertain to the peculiar metaphysical setting in which the arguments occur. Now since, on Waterlow's account, this metaphysical setting centrally involves the notion of omnitemporality, and inasmuch as she also endeavors to explain how these same modalities operate in Aristotle's discussion of future contingents in De Interpretatione 9, her basic thesis is that for Aristotle, modal and temporal notions never merge, but occasionally mingle. (shrink)

This chapter contains sections titled: * Incoherency Objections * Objections to Theistic Arguments * Empirical Arguments a gainst God’s Existence * References * Further Reading.