Al-Fārābī, in the Kitāb al-Ḥurūf, is apparently the first person to maintain that existence, in one of its senses, is a second-order concept [ma‘qūl thānī]. As he interprets Metaphysics Δ7, ‘‘being'' [mawjūd] has two meanings, second-order ‘‘being as truth'', and first-order ‘‘being as divided into the categories.'' The paronymous form of the Arabic word ‘‘mawjūd'' suggests that things exist through some existence [wujūd] distinct from their essences: for al-Kindī, God is such a wujūd of all things. Against this, al-Fārābī argues (...) that existence as divided into the categories is real but identical with the essence of the existing thing, and that existence as truth is extrinsic to the essence but non-real. The Ḥurūf tries to reconstruct the logical syntax of syncategorematic or transcendental concepts such as being, which are often expressed in misleading grammatical forms. Al-Fārābī thinks that Greek more appropriately expressed many such concepts, including being, by particles rather than nouns or verbs; he takes Metaphysics Δ to be discussing the meanings of such particles, and he takes these concepts to demarcate the domain of metaphysics. This explains how al-Fārābī's title can mean both ‘‘Book of Particles'' and ‘‘Aristotle's Metaphysics.''. (shrink)

: Dennis Des Chene's Physiologia: Natural Philosophy in Late Aristotelian and Cartesian Thought reconstructs the discourse of late scholastic natural philosophy, and assesses Descartes' agreements and disagreements. In a critical discussion, I offer a different interpretation of late scholastic theories of final causality and of God's concursus with created efficient causes. Fonseca's and Suárez' conceptions of final causality in nature depend on their claim that a single action can be the action of two agents at once--in particular, of God and (...) of a creature. I discuss both their theory of action and its implications for natural teleology. I then compare Descartes, emphasizing his demolition of the Aristotelian hierarchy of causes, with unmoved movers (culminating in God) regulating the action of inferior moved movers. Aristotle argues that unmoved causes are needed to produce a stable world-order; he takes arts (tÁxnai) as his models of unmoved causes, and uses this model to support natural teleology. Descartes radically simplifies this system by denying all unmoved movers other than God, and denying anything analogous to an art in non-human nature. I explore the implications for Descartes' notion of concursus and his criticism of natural teleology, and discuss his resulting difficulties in explaining natural stability. (shrink)

Dennis Des Chene's Physiologia: Natural Philosophy in Late Aristotelian and Cartesian Thought reconstructs the discourse of late scholastic natural philosophy, and assesses Descartes' agreements and disagreements. In a critical discussion, I offer a different interpretation of late scholastic theories of final causality and of God's concursus with created efficient causes. Fonseca's and Suárez' conceptions of final causality in nature depend on their claim that a single action can be the action of two agents at once--in particular, of God and of (...) a creature. I discuss both their theory of action and its implications for natural teleology. I then compare Descartes, emphasizing his demolition of the Aristotelian hierarchy of causes, with unmoved movers regulating the action of inferior moved movers. Aristotle argues that unmoved causes are needed to produce a stable world-order; he takes arts as his models of unmoved causes, and uses this model to support natural teleology. Descartes radically simplifies this system by denying all unmoved movers other than God, and denying anything analogous to an art in non-human nature. I explore the implications for Descartes' notion of concursus and his criticism of natural teleology, and discuss his resulting difficulties in explaining natural stability. (shrink)

When Aristotle speaks of theologikê, he means not the study of a single God, but the study of gods and divine things in general. He never uses the phrase “the unmoved mover” to pick out just one being, and that phrase would not express the essence of the beings it applies to. To see what sort of religious interest there might be in such a being, and how the words “god” and “divine” enter into Aristotle's philosophy, it is best to (...) start with what he says about gods and divine things in moral and political contexts. Guided by his criticisms of Plato on the soul's self-motion, Aristotle sets out, in Physics VIII, to give a revised version of Plato's cosmotheological argument in Laws X. This article focuses on Aristotle's theology and his views about gods, the soul, the cosmos, heavens and heavenly bodies, and the first principle or first cause. (shrink)

"Anton Wilhelm Amo is the first modern African philosopher to study and teach in a European university and write in the European philosophical tradition. We give an extensive historical and philosophical introduction to Amo's life and work, and provide Latin texts, with facing translations and explanatory notes, of Amo's two philosophical dissertations, On the Impassivity of the Human Mind and the Philosophical Disputation containing a Distinct Idea of those Things that Pertain either to the Mind or to our Living and (...) Organic Body, both published in 1734. The Impassivity is an extended argument that the mind cannot be acted on, that sensation is a being-acted-on by the sensed object, and therefore that sensation does not belong to the mind, and must belong instead to the body The Distinct Idea works out the implications for the mind's actions, and tries to show how the mind understands, wills, and effects things through the body by 'intentions' which direct motions in our body intentionally toward external things. Both dissertations try to show how far each type of human act belongs to the mind, how far to the body, and expose and resolve earlier philosophers' self-contradictions on these questions"--. (shrink)

Al-Fbb al-f, is apparently the first person to maintain that existence, in one of its senses, is a second-order concept [mal th]. As he interprets Metaphysics d] has two meanings, second-order being as truth'' (including existence as well as propositional truth), and first-order being as divided into the categories.'' The paronymous form of the Arabic word mawjd] distinct from their essences: for al-Kindd of all things. Against this, al-Fburr thinks that Greek more appropriately expressed many such concepts, including being, by (...) particles rather than nouns or verbs; he takes Metaphysics r's title can mean both Book of Particles'' and Aristotle's Metaphysics.''. (shrink)

Here I reexamine Duhem's question of the continuity between medieval dynamics and early modern conservation theories. I concentrate on the heavens. For Aristotle, the motions of the heavens are eternally constant (and thus mathematizable) because an eternally constant divine Reason is their mover. Duhem thought that impetus and conservation theories, by extending sublunar mechanics to the heavens, made a divine renewer of motion redundant. By contrast, I show how Descartes derives his law of conservation by extending Aristotelian celestial dynamics to (...) the earth. Descartes argues that motion is intrinsically linear, not circular. But he agrees that motion is mathematically intelligible only where divine Reason moves bodies in a constant and eternal motion. Descartes strips bodies of active powers, leaving God as the only natural mover; thus both celestial and sublunar motions are constant, and uniformly mathematizable. The law of conservation of the total quantity of motion is an attempt to harmonize the constancy derived a priori with the phenomenal inconstancy of sublunar motions. (shrink)

This book is a systematic study of Descartes' relation to Augustine. It offers a complete reevaluation of Descartes' thought and as such will be of major importance to all historians of medieval, neo-Platonic, or early modern philosophy. Stephen Menn demonstrates that Descartes uses Augustine's central ideas as a point of departure for a critique of medieval Aristotelian physics, which he replaces with a new, mechanistic anti-Aristotelian physics. Special features of the book include a reading of the Meditations, a comprehensive (...) historical and philosophical introduction to Augustine's thought, a detailed account of Plotinus, and a contextualization of Descartes' mature philosophical project which explores both the framework within which it evolved and the early writings, to show how the collapse of the early project drove Descartes to the writings of Augustine. (shrink)

This book is the first sustained modern investigation of Plato’s theology. A central thesis of the book is that Plato _had _a theology—not just a mythology for the ideal city, not just the theory of forms or the theory of cosmic souls, but also, irreducible to any of these, an account of God as _Nous _, the source of rational order both to souls and the world of bodies. The understanding of God as Reason, and of the world as governed (...) directly or indirectly by Reason, is worked out in the dialogues of Plato’s last period, the _Statesman, Philebus, Timaeus, _and _Laws. _These dialogues offer a strategy for explaining the physical world that goes beyond anything in the middle dialogues, and gives the best starting point for understanding the cosmologies and theologies of Aristotle, the Stoics, and later ancient thinkers. Menn focuses on the _Timaeus _as Plato’s most sustained effort to provide what _Anaxagoras had failed to deliver: an explanation of the world through Reason, showing that things are as they are because it is best, or because it best serves the order of the world as a whole. Anaxagoras was disappointed because he explained things through their material constituents, without explaining why the constituents are ordered as they are; but the theory of forms has the same defect, since it_ _cannot explain why different parts of the universe participate in different forms according to a particular order. The _Timaeus _and other late dialogues attempt to supply the missing explanation of the ordering of the physical world. These dialogues do not retreat from the middle dialogue theory of forms, nor do they escape into an esoteric theory of numbers; but they add to the middle dialogues an analysis of the principles necessary to account for the existence and partial intelligibility of the sensible world—not only forms and a material substance but also _Nous _and souls. Although the demiurge of the _Timaeus _ _is represented as a cause both to souls and bodies, most scholars have been reluctant to identify the demiurge as a being separate from and superior to souls, because they think that both the meaning of the Greek word _nous _and Plato’s own statements require that _Nous _is_ _either a kind of soul or something inseparable from souls. Reexamining the linguistic evidence and the Platonic texts, Menn argues that _nous _can mean something separate from souls, namely the virtue of rationality or intelligence that souls participate in. Menn argues that Anaxagoras’ _Nous _should be construed as such a virtue; then he examines what status this virtue has in the context of the Platonic theory of forms, and how it_ _is a cause both to souls and to bodies. Soul plays a crucial role in mediating the causality of _Nous _and introducing rational order into the world of bodies, but neither soul in general nor the world-soul in particular can be identified with _Nous. _ Menn stresses the pre-Socratic context for the cosmology and theology of Plato’s late dialogues; he argues for the importance of Diogenes of Appolonia in particular, and he reconstructs a possible new fragment of Diogenes from the _Timaeus _and from the Hippocratic treatise _On Breaths. _In the _Timaeus _and other late dialogues Plato attempts to do better than his predecessors by standards implicit in Socrates’ critique of Anaxagoras in the _Phaedo, _but what Plato offers remains consciously provisional. Aristotle argues that the _Timaeus _remains liable to some of the same criticisms that Socrates had leveled against Anaxagoras, and Aristotle’s own cosmology and theology take up Plato’s challenge to carry out Anaxagoras’ promise of an explanation of the world through _Nous, _and attempt to improve on the _Timaeus _as_ _Plato had improved on Anaxagoras. In this way the _Timaeus _serves as an essential starting point, not only_ _for those later ancient philosophers who took it as an authoritative statement on the world and on God but also for those who took it as a challenge to do better. (shrink)

This chapter contains sections titled: Xenophon and the Socratic Question The Main Differences Between SocratesX and SocratesP SocratesX and Enkrateia Reworking of Socratic Themes on the Basis of Enkrateia Akrasia Enkrateia and Autarkeia One Socrates and Many.

ARISTOTLE PRESENTS HIS DOCTRINE OF GOD as the first unmoved mover as the crown of his metaphysics, and thus of his entire theoretical philosophy. He obviously considers it an important achievement. Yet the doctrine has been peculiarly resistant to interpretation. It is difficult to know where to break in to Aristotle's theology: certainly not with his proof that the first mover must be unmoved. The proof has clearly been developed for the sake of the conclusion and not vice versa. How (...) did this conclusion occur to Aristotle, and why did he want it to be true? (shrink)

A narrow focus on the jaw (or on motor generators) does not account for individual and language-specific differences in babbling and early speech. Furthermore, data from Yoshinaga-Itano's laboratory support earlier findings that show glottal rather than oral stops in deaf infants' babbling: audition is crucial for developing normal syllables.

Aristotelian Philosophy, as far as its subject matter is Being, conceives of it as “ousia,” substance. This actual, self-sufficient Being contrasts with the dependent Being of the “symbekóta,” accidents, nonsubstantial attributes. Real Being, existence was of no interest for Antique Philosophy. It was as late as in Scholastic Philosophy that the concept of “existere” gained interest in connection with the problem of universals and the proofs of God’s existence. Albert the Great uses this concept in connection with the concept of (...) a person. (shrink)

29 o JOURNAL OF THE HISTORY OF PHILOSOPHY 34:2 APRIL t996 J. Burnet, Oxford, 19oz ) is excluded, as are influential works in foreign languages. Popper's The Open Society and Its Enemies, vol. I is included 077); it was later translated into German . The converse does not hold: P. Friedl~inder's Platon 049-43) is included, but its English translation is not. F. Solmsen's Plato's Theology is not included, nor is his "Plato and the Unity of Science,"s although it was reprinted (...) in Solmsen's Kleine Schriften4 and Soimen's German articles reprinted there are included. As the international Plato Forschungsberichte of Ritter5 demonstrate even for the Germany of the early decades of this century, the world of scholarship knows no national bound- aries. The present attempt to impose them on Platonic studies results in a highly artificial work of bibliography. 6 RICHARD McKIRAHAN Pomona College Carl A. Huffman. Philolaus of Croton, Pythagorean and Presocratic: A Commentary on the Fragments and Testimonia with Interpretive Essays. New York: Cambridge University Press, 1993. Pp. xix + 444- Cloth, $1oo.oo. Pythagoreanism used to play a major role in accounts of Presocratic philosophy. Follow- ing the testimony of ancient Platonists, the Pythagoreans were seen as Plato's precur- sors in cosmology, on the soul, and on Ideas and numbers; and attempts were made to reconstruct the systematic philosophy of the Pythagoreans, or even of Pythagoras himself. Now, however,.. (shrink)

Aristotle in Physics I,1 says some strange-sounding things about how we come to know wholes and parts, universals and particulars. In explicating these, Simplicius distinguishes an initial rough cognition of a thing as a whole, an intermediate "cognition according to the definition and through the elements," and a final cognition of how the thing's many elements are united: only this last is επιστημη. Simplicius refers to the Theaetetus for the point about what is needed for επιστημη and the ways that (...) cognition according to the definition and through the elements falls short. By unpacking this reference I try to reconstruct Simplicius' reading of "Socrates' Dream," its place in the Theaetetus ' larger argument, and its harmony with other Platonic and Aristotelian texts. But this reconstruction depends on undoing some catastrophic emendations in Diels's text of Simplicius. Diels's emendations arise from his assumptions about definitions and elements, in Socrates' Dream and elsewhere, and rethinking the Simplicius passage may help us rethink those assumptions. (shrink)

J'examine le statut et la fonction des Catégories dans la philosophie d'Aristote.Le traité n'appartient ni à la philosophie première, ni même à la philosophie tout court, mais à la dialectique. Il ne s'agit pas d'une « discussion dialectique » de l'être, mais plutôt de dialectique en tant que tel : ce traité forme un ensemble avec les Topiques, qui a pour but d'aider le questionneur dans un débat dialectique à décider si le terme donné peut tomber sous la définition proposée (...) ou sous le genre proposé. Bien qu'il y ait un emploi philosophique des Catégories, tout comme de la dialectique en général, l'opposition prétendue entre la théorie de la substance des Catégories et celle de la Métaphysique est fondée sur une méconnaissance des buts différents des deux traités. I examine the status and function of the Categories in Aristotle's philosophy.The work does not belong to « first philosophy, » or indeed to philosophy at all, but to dialectic; not as a « dialectical discussion » of being, but in the strict sense that it is intended, together with the Topics, to help the dialectical disputant to decide whether a given term can fall under a proposed definition or a proposed genus. Although the Categories, like dialectic in general, has uses in philosophical argument, the supposed opposition between the accounts of substance in the Categories and in the Metaphysics depends on a misunderstanding of the different aims of the two works. (shrink)

In this paper I reexamine Plato's method of collection and division, and specifically of collection. If collection and division are simply methods for mapping out genus-species trees, then it is hard to understand why Plato is so excited about them. But a close study of Plato's examples shows that these methods are something broader, and shows why Plato would regard collection as an important tool for coming to know "elements" in any domain of inquiry. In the first section I focus (...) on a notoriously problematic example of collection from the "Philebus," Theuth's discovery of the letters of the alphabet; I show how Plato interprets this discovery as a process of collection, and draw conclusions about what Plato takes collection to be. In the process, I try to bring out Plato's analysis of what is involved in learning to read and write a language, which he takes as paradigmatic for other knowledge. In the second section, stepping back from the "Philebus" passage and applying its lessons, I describe the function of collection and division, for the late Plato, in coming to know "elements," including the Forms, or the most basic Forms. Reflection on Plato's use of collection suggests a (relatively non-mystical) account of what it is to know non-complex intelligible entities, and of how we can come to know them. I also use Plato's descriptions of collection and division to suggest a Platonic context for the notion of the separation of the Forms, to which the late Plato remains firmly committed. (shrink)

The “lost” Yaḥyā ibn ʿAdī treatises recently discovered in the Tehran codex Marwī 19 include a record of a philosophical debate instigated by the Ḥamdānid prince Sayf-al-Dawla. More precisely, Marwī 19 contains Yaḥyā’s adjudication of a dispute between an unnamed Opponent and Yaḥyā’s younger relative Ibrāhīm ibn ʿAdī (who also served as al-Fārābī’s assistant), along with Ibrāhīm's response to Yaḥyā’s adjudication, and Yaḥyā’s final word. At issue was a problem of Aristotelian exegesis: should “body” be understood as falling under the (...) category of substance or under the category of quantity? The unnamed Opponent argues that body is a species of substance; Ibrāhīm argues that technically speaking, body is a species of quantity, and hence an accident; and Yaḥyā judges that body is a species of substance, though for very different reasons than the Opponent gives. For the first time, the Arabic text of this exchange is edited and translated into English. Also provided is an Introduction that sets the debate in historical context, and discusses in particular the possible influence of John Philoponus. The debate is interesting and important not only because of the philosophical ramifications of the issues under discussion, but because it constitutes evidence of dialectical practice among Arabic-speaking philosophers from the middle of the 10th century. (shrink)

Gyorgy Tamas works in the philosophy of logic, that difficult interdisciplin ary region wherein the notion of categories is both basic and subtle. To understand ways of thinking, to understand patterns of whatever is real, to recognize what is possible and to reject the nonsensical and the impossible is to comprehend the categories. This was a in thought and in fact, recurring motive of European thought from the earliest self-aware beginnings, and Tamas knows that history well, as his critical respect (...) demonstrates. Ancient, medieval, and modern thinkers appear in this book, set forth in their own words; and likewise we see that Tamas has built upon the historians and commentators, upon the pioneering historical investigation of the categories by Trendelenburg a century ago and by Bochenski in our days. Tamas has two principal goals here: to investigate the logic, which is to say the structure and the relations, of the philosophical categories; and to set forth the logic of thought which may then be based upon the critically established system of categories obtained by that investigation. Ancillary but of striking value is his style of historical relevance which enables the reader to engage in a discussion that is both analytically sharp and developmentally insightful. Furthermore, Tamas draws upon his contem porary colleagues with similar critical respect: Lukasiewicz, Quine, Patzig, Menne, Tavanets and others. (shrink)

Duhem regarded the history of physical science as carrying a twofold lesson for the practicing physicist. First, history revealed the slow, groping, yet continuous development of physical theory toward a true description of the relations among natural entities. Second, history also unmasked false explanations and metaphysical beliefs that might seduce the unwary scientist into following an unfruitful line of research. This paper brings forth the central images underlying Duhem's historiographical project and uses the papers by S. Menn and W. (...) A. Wallace to ask what Duhem's enterprise actually meant in practice. I argue that the main question is the following: What is to count as the proper space of historical meaning and explanation? Strong Duhemians, such as S. Menn, purchase the longue durée at the cost of making historical agents into completely passive transmitters of conceptual homologies; weak Duhemians, such as W. A. Wallace, shorten the temporal distance between agents and permit thereby a modicum of conflict and negotiation within physical theory while still seeking to preserve long-term conceptual genealogies. Both positions, it is argued, allow insufficient room for actors' categories to determine the space of cultural analysis. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Reviewed by:Hellenistic and Early Modern PhilosophyChristopher S. CelenzaJon Miller and Brad Inwood, editors. Hellenistic and Early Modern Philosophy. New York: Cambridge University Press, 2003. Pp. xii + 330. Cloth, $60.00.There are at least two ways of writing the history of philosophy: the first and most common among those self-identified as "philosophers" treats philosophers of the past as if they were in live dialogue with the present. Only the text (...) is dissected, studied, and analyzed as the interpreter attempts to reconstruct, examine, and occasionally challenge the arguments under consideration. Practitioners of this first way assume that systematic and seemingly internally coherent styles of thought are most worthy of the name "philosophy." These thinkers believe that the term "philosophy," as Richard Rorty pointed out long ago, has an "honorific" sense: philosophy as such stands above other forms of thought, it is regulative in scope, and it serves as something that examines the conclusions of other, necessarily less rigorous fields. The second way is more explicitly contextualist, seeking to understand what a past thinker may have meant in his own time, what outside factors may have shaped his arguments, and how his thought may be part of broader historical currents that are none the less worthy of being remembered and studied now. Practitioners of this way are more likely to believe that ambiguities or seeming deficiencies of clarity that we find in the work of a past thinker are unlikely to be resolved by hypothetical, propositional reconstruction; rather the ambiguities are apparent to us because we are differently situated, so that the study of history is a more powerful tool in helping us satisfactorily access the work of a past thinker than rationalistic reconstruction. (Full disclosure: I am an advocate of the second way.) This volume presents studies that fall into both of the two camps, as Jerome Schneewind points out in his cogent introduction.The volume has a manifest unity: almost all of the articles are concerned in some way with different Hellenistic schools of thought and the way early modern thinkers used, re-imagined, and interpreted them. The studies are often meticulous and all are stimulating. Anthony Long offers a wonderfully synthetic presentation of ancient Stoicism as a coherent system, after which he examines the way Spinoza, Justus Lipsius, and the eighteenth-century Anglican bishop Joseph Butler measure up; unsurprisingly, they don't measure up that well. Margaret Osler seeks to illuminate the way Gassendi appropriated certain aspects of Epicureanism. Philip Mitsis argues that modern scholarship on Locke has not taken Locke's interest in Cicero's De officiis as a tool for teaching morality seriously. Donald Rutherford studies Leibniz's critique of Stoicism, which "centers," he writes, on their "failure to offer an adequate explanation of the nature of moral progress and of the dependence of human happiness on the hope for such progress" (62-63). Catherine Wilson presents a study of the corpuscular aspect of Epicurean natural philosophy among Leibniz and his contemporaries. Jon Miller eloquently and thoughtfully discusses the way Grotius and Spinoza worked with the natural law theory of the Stoics. Among a number of excellent articles, perhaps the most interesting is Stephen Menn's. Menn makes a compelling case that Descartes's intellectual autobiography in the Discourses may be seen as part of a tradition. In it, the writer presents himself as reaching a moment of dissatisfaction with the intellectual customs with which he has come into contact and as needing to strike off into new directions, unencumbered by the vestiges of those customs. While others, most notably Dan Garber, have shown that, as Menn puts it, "none of Descartes's contemporaries seem to have thought in 1637 that they were witnessing a revolution" (142), Menn's study is striking because it shows the depth of the tradition within which Descartes was working. Next, Gail Fine finds that the Cyrenaics, as presented by Sextus Empiricus, seem to have [End Page 207] endorsed "the view that there are truths, beliefs, and knowledge about the subjective" (214). Steven Nadler seeks to show that there is no mysticism in Spinoza's thought, even though it was not uncommon in Spinoza's own day to... (shrink)

This review article devoted to Stephen Menn's Descartes and Augustine, finds that his treatment of Augustine which includes him within the metaphysical tradition bridging antiquity and modernity balances the historicist, anti-metaphysical and anti-theoretical readings of Augustine coming from postmodern philosophy and theology. By looking at the two readings together, Wayne Hankey attempts to come closer to an understanding of Augustine especially in his relation to Plotinus. Hankey finds that Augustine's De Trinitate is better understood from within Menn's stance, (...) where Augustine is placed together with Plotinus and Descartes. Within that view, we are better able to understand Augustine's difference from Plotinus than from the alternative postmodern perspective. However he judges that Menn does not draw Augustine's theology closely enough together with philosophy. When that is done, what in Augustine lays the foundations for autonomous philosophy will be more fully known. (shrink)

In recent years, Early Modern Philosophy has seen frequent and urgent calls for more diverse, equitable, and inclusive teaching and research. These are calls fo.

From the topics discussed by Hattab and Menn, I examine two of special importance. The first is that of active powers: does the Cartesian natural world contain any, or is the apparent efficacy of natural agents always to be referred to God? In arguing that it is, I consider, following Hattab, Descartes' characterization of natural laws as "secondary causes." The second topic is that of ends. Menn argues, and I agree, that in late Aristotelianism Aristotle's own conception of (...) an "art in things" has been abandoned. The point is reinforced when one considers the general divine ends which must be invoked in cases of aborted action. In them no individual agent attains its end. Yet Nature as a whole continues to act toward ends. I suggest that those general ends, to which Suárez, for example, refers, may have served later philosophers, especially Malebranche, in combining the Cartesian notion of law with a teleological interpretation of nature that Descartes, for his part, rejected. (shrink)

In this paper we assess the explanatory role of idealizations in ‘design explanations’, a type of functional explanation used in biology. In design explanations, idealizations highlight which factors make a difference to phenomena to be explained: hypothetical, idealized, organisms are invoked to make salient which traits of extant organisms make a difference to organismal fitness. This result negates the view that idealizations serve only pragmatic benefits, and complements the view that idealizations highlight factors that do not make a difference. This (...) analysis in particular strengthens the perspective that idealizations are means to highlight difference making factors, and identifies a novel, more direct role for idealizations in doing so. It thus offers a novel argument why in some explanatory contexts idealizations are in-eliminable. (shrink)