Edward Zalta

The arguments of the dialetheists for the rejection of the traditional law of non-contradiction are not yet conclusive, for they uniformly fail to consider how the logic of encoding undermines the problems dialetheism solves. This chapter treats historical philosophical problems, discussed in Priest (1995), in the logic of encoding. The argument at the heart of the case against the law of non-contradiction (i.e. the argument based on the paradoxes of self-reference) is also re-analyzed in the light of encoding logic. The chapter concludes with a more general discussion of logic and predication, and with the suggestion that there is no need to tamper with the logic of the traditional mode of predication if there is an alternative mode of predication that is well suited to the analysis of cases involving contradictory objects.

Two recent arguments draw startling and puzzling conclusions about relations and 2nd-order logic (2OL). The first argument concludes that 2nd-order quantifiers can’t be interpreted as ranging over relations. This conclusion is puzzling because it calls into question the traditional understanding of 2OL as a formalism for quantifying over relations. The second argument, which concludes that unwelcome consequences arise if relations and relatedness are analyzed rather than taken as primitive, utilizes premises that imply that 2OL faces the very same consequences. This is puzzling because relations and predication are taken as primitive in 2OL, and so the latter should be immune to the problems raised for the analysis of relations. I consider these two arguments in light of a precise theory of relations. In particular, I show that object theory [@zalta:1983; @zalta:1988], which is an extension of 2OL, provides systematic existence and identity conditions for relations, properties, and states of affairs that forestall the two arguments.

Any uniform semantic treatment of fictional names (e.g., ‘Frodo’) across parafictional statements (e.g., ‘In The Lord of the Rings, Frodo was born in the Shire’) and metafictional statements (e.g., ‘Frodo was invented by Tolkien’) runs into a variation of the ‘wrong kind of object’ problem. The problem arises when an analysis of one of these statements inappropriately attributes a property to an object. For example, it would be problematic if an analysis implied that flesh and blood individuals are invented by someone, and similarly problematic if an analysis implied that abstract objects are born in a certain region. Abstract object theory has provided a solution to this conundrum by distinguishing two modes of predication: encoding and exemplifying. Recently Klauk has argued that the problem reappears for the analysis of explicit parafictional statements in this theory. In this paper we formalize the objection and show that one can distinguish three issues in connection with the ‘wrong kind of object’ problem. We then address them in turn.

In this paper, the authors show that there is a reading of St. Anselm’s ontological argument in Proslogium II that is logically valid (the premises entail the conclusion). This reading takes Anselm’s use of the definite description “that than which nothing greater can be conceived” seriously. Consider a first-order language and logic in which definite descriptions are genuine terms, and in which the quantified sentence “there is an x such that…” does not imply “x exists”. Then, using an ordinary logic of descriptions and a connected greater-than relation, God’s existence logically follows from the claims: (a) there is a conceivable thing than which nothing greater is conceivable, and (b) if x does not exist, something greater than x can be conceived. To deny the conclusion, one must deny one of the premises. However, the argument involves no modal inferences and, interestingly, Descartes’ ontological argument can be derived from it.

We argue that logicism, the thesis that mathematics is reducible to logic and analytic truths, is true. We do so by (a) developing a formal framework with comprehension and abstraction principles, (b) giving reasons for thinking that this framework is part of logic, (c) showing how the denotations for predicates and individual terms of an arbitrary mathematical theory can be viewed as logical objects that exist in the framework, and (d) showing how each theorem of a mathematical theory can be given an analytically true reading in the logical framework.

In this article, I show how two modes of predication and quantification in a modal context allow one to (a) define what it is for an individual or relation to exist, (b) define identity conditions for properties and relations conceived hyperintensionally, (c) define identity conditions for individuals and prove the necessity of identity for both individuals and relations, (d) derive the central definition of free logic as a theorem, (e) define the essential properties of abstract objects and provide a framework for defining the essential properties of ordinary objects, and (f) derive a theory of truth. I also describe my indebtedness to the work of Terence Parsons and take the opportunity to advance the discussion in connection with an objection raised to the theory of essential properties.

Science provides us with representations of atoms, elementary particles, polymers, populations, genetic trees, economies, rational decisions, aeroplanes, earthquakes, forest fires, irrigation systems, and the world’s climate. It's through these representations that we learn about the world. This entry explores various different accounts of scientific representation, with a particular focus on how scientific models represent their target systems. As philosophers of science are increasingly acknowledging the importance, if not the primacy, of scientific models as representational units of science, it's important to stress that how they represent plays a fundamental role in how we are to answer other questions in the philosophy of science (e.g. the scientific realism debate). This entry begins by disentangling ‘the’ problem of scientific representation, before critically evaluating the current options available in the literature.

The arguments of the dialetheists for the rejection of the traditional law of noncontradiction are not yet conclusive. The reason is that the arguments that they have developed against this law uniformly fail to consider the logic of encoding as an analytic method that can resolve apparent contradictions. In this paper, we use Priest [1995] and [1987] as sample texts to illustrate this claim. In [1995], Priest examines certain crucial problems in the history of philosophy from the point of view of someone without a prejudice in favor of classical logic. For each of these problems, the logic of encoding offers an alternative explanation of the phenomena---this alternative is not considered when Priest describes what options there are in classical logic for analyzing the problem at hand.

The arguments of the dialetheists for the rejection of the traditional law of noncontradiction are not yet conclusive. The reason is that the arguments that they have developed against this law uniformly fail to consider the logic of encoding as an analytic method that can resolve apparent contradictions. In this paper, we use Priest [1995] and [1987] as sample texts to illustrate this claim. In [1995], Priest examines certain crucial problems in the history of philosophy from the point of view of someone without a prejudice in favor of classical logic. For each of these problems, the logic of encoding offers an alternative explanation of the phenomena---this alternative is not considered when Priest describes what options there are in classical logic for analyzing the problem at hand. The argument at heart of the case that Priest develops against the law of noncontradiction (i.e., the argument based on the paradoxes of self-reference) is then reanalyzed in light of encoding logic. After showing why the argument is inconclusive, the paper concludes both with a more general discussion of logic and predication and with the suggestion that there is no need to tamper with the logic of the traditional mode of predication if there is alternative mode of predication which is well-suited to the analysis of cases involving contradictory objects.

In this paper, the author analyzes critically some of the ideas found in Karel Lambert's recent book, Meinong and the Principle of Independence (Cambridge: Cambridge University Press, 1983). Lambert attempts to forge a link between the ideas of Meinong and the free logicians. The link comes in the form of a principle which, Lambert says, these philosophers adopt, namely, Mally's Principle of Independence, which Mally himself later abandoned. Instead of following Mally and attempting to formulate the principle in the material mode as the claim that an object can have properties without having any sort of being, Lambert formulates the principle in the formal mode, as (something equivalent to) the rejection of the traditional constraint on the principle of predication. The principle of predication is that a formula of the form Fa' is true iff the general term F' is true of the object denoted by the object term a'. The traditional constraint on this predication principle is that for the sentence Fa' to be true, not only must the object term have a denotation, but it must also denote an object that has being. According to Lambert, the free logicians violate this constraint by suggesting that Fa' can be true even if the object term has no denotation, whereas Meinong violates this constraint by proposing Fa' can be true even when the object term denotes an object that has no being. Lambert then tries to `vindicate' the Principle of Independence, thereby justifying both the work of the free logicians and Meinong.

This paper investigates two forms of the Routley star operation, one in Routley & Routley 1972 and the other in Leitgeb 2019. We use the background of object theory to define both forms of the Routley star operation and show how the basic principles governing both forms become derivable and need not be stipulated. Since no mathematics is assumed by our background formalism, the existence of the Routley star image s* of a situation s is therefore guaranteed not by set theory but by a theory of abstract objects. The work in the paper integrates Routley star into a more general theory of (partial) situations that has previously been used to develop the theory of possible worlds and impossible worlds.

We address the following questions in this paper: (1) Which set or number existence axioms are needed to prove the theorems of ‘ordinary’ mathematics? (2) How should Frege’s theory of numbers be adapted so that it works in a modal setting, so that the fact that equivalence classes of equinumerous properties vary from world to world won’t give rise to different numbers at different worlds? (3) Can one reconstruct Frege’s theory of numbers in a non-modal setting without mathematical primitives such as “the number of Fs” ( $$\#F$$ ) or mathematical axioms such as Hume’s Principle? Our answer to question (1) is ‘None’. Our answer to question (2) begins by defining ‘x numbers G’ as: x encodes all and only the properties F such that being-actually-F is equinumerous to G with respect to discernible objects. We answer (3) by showing that the mere existence of discernible objects allows one to reconstruct Frege’s derivation of the Dedekind-Peano axioms in a non-modal setting.

Karen Bennett has recently argued that the views articulated by Linsky and Zalta (Philos Perspect 8:431–458, 1994) and (Philos Stud 84:283–294, 1996) and Plantinga (The nature of necessity, 1974) are not consistent with the thesis of actualism, according to which everything is actual. We present and critique her arguments. We first investigate the conceptual framework she develops to interpret the target theories. As part of this effort, we question her definition of ‘proxy actualism’. We then discuss her main arguments that the theories carry a commitment to actual entities that do not exist. We end by considering and addressing a worry that might have been the driving force behind Bennett’s claim that Linsky and Zalta’s view is not fully actualistic.

A formula is a contingent logical truth when it is true in every model M but, for some model M , false at some world of M . We argue that there are such truths, given the logic of actuality. Our argument turns on defending Tarski’s definition of truth and logical truth, extended so as to apply to modal languages with an actuality operator. We argue that this extension is the philosophically proper account of validity. We counter recent arguments to the contrary presented in Hanson’s ‘Actuality, Necessity, and Logical Truth’ (Philos Stud 130:437–459, 2006 )

In this paper, we investigate (1) what can be salvaged from the original project of "logicism" and (2) what is the best that can be done if we lower our sights a bit. Logicism is the view that "mathematics is reducible to logic alone", and there are a variety of reasons why it was a non-starter. We consider the various ways of weakening this claim so as to produce a "neologicism". Three ways are discussed: (1) expand the conception of logic used in the reduction, (2) allow the addition of analytic-sounding principles to logic so that the reduction is not to "logic alone" but to logic and truths knowable a priori, and (3) revise the conception of "reducible". We show how the current versions of neologicism fit into this classification scheme, and then focus on a kind of neologicism which we take to have the most potential for achieving the epistemological goals of the original logicist project. We argue that that the "weaker" the form of neologicism, the more likely it is to be a new form of logicism, and show how our preferred system, though mathematically weak, is metaphysically and epistemogically strong, and can "reduce" arbitrary mathematical theories to logic and analytic truths, if given a legitimate new sense of "reduction".

In this paper, we develop an alternative strategy, Platonized Naturalism, for reconciling naturalism and Platonism and to account for our knowledge of mathematical objects and properties. A systematic (Principled) Platonism based on a comprehension principle that asserts the existence of a plenitude of abstract objects is not just consistent with, but required (on transcendental grounds) for naturalism. Such a comprehension principle is synthetic, and it is known a priori. Its synthetic a priori character is grounded in the fact that it is an essential part of the logic in which any scientific theory will be formulated and so underlies (our understanding of) the meaningfulness of any such theory (this is why it is required for naturalism). Moreover, the comprehension principle satisfies naturalist standards of reference, knowledge, and ontological parsimony! As part of our argument, we identify mathematical objects as abstract individuals in the domain governed by the comprehension principle, and we show that our knowledge of mathematical truths is linked to our knowledge of that principle.