The article is devoted to identifying the concept of the meaning of life in the critical philosophy of A.I. Vvedensky, where special attention is paid to the methodological foundations and the historical and philosophical context. The formulation of the question about the meaning of life is one of the ultimate questions in philosophy, the answer to which makes it possible to determine the motives of human activity. In Vvedenskyʼs philosophy, the problem of goal-setting in life is revealed in the prism (...) of a key research intention – the construction of a scientifically revised worldview based on the principles of criticism. As a result, the question of life and its purpose is reduced to the formulation of the question of the logical permissibility and boundaries of questioning. The article attempts to reconstruct the philosopherʼs reasoning and identify the most significant definitions, which include morality, mental life, and the purpose of life. The disclosure of the concept of life in Vvedenskyʼs philosophy invariably requires consideration of the context in which the development of the philosopherʼs ideas takes place. Based on a comprehensive analysis, it is concluded that the concept of life is an extension of the main goal of Vvedenskyʼs research – the disclosure of the conditions for the formation of a reliable worldview, focused on the principles of scientific knowledge in accordance with moral values. Another important consequence is the provision on the priority of morality in relation to scientific and philosophical knowledge. The foundations of morality, to which the meaning of life belongs, can be presented only in a special form of applicability of critical reason – critical faith. Thus, the question of the specifics of critical metaphysics and the importance of differentiation of types and forms of faith in the work of the Russian neo-Kantian are clarified. (shrink)

Russian neo-Kantianismʼs status in the history of the development of Russian philosophy is an important, but poorly presented in scientific publications, issue is revealed in the article. With some exceptions, which are represented by a number of few, but informative and informative articles and a monograph, the problem remains without proper reception in the scientific discourse of our time. Russian neo-Kantianism, however, leaving aside the question of what is the phenomenon of Russian neo-Kantianism, it is impossible to productively and consistently (...) actualize the content of Russian neo-Kantians and, moreover, to show their significance in the history of Russian philosophical and socio-humanitarian thought in general. Three key difficulties stand out: 1) the question of originality and the related theme of the independence of the philosophical direction (originality, independence and originality – differ from each other, but are united in their immanent orientation); 2) Russian neo-Kantianism, which in many ways seems to be the most difficult task for researchers engaged in historical and philosophical reconstruction; 3) the question remains ambiguous as to whether Russian neo-Kantianism is a continuation of the German tradition or whether it is a direction of Russian philosophy of thought. Russian neo-Kantianism, the three difficulties identified in the reception of the phenomenon of Russian neo-Kantianism taken as a whole, are consistently revealed in the content of the proposed article, supplemented by a brief overview of the most systemic positions of Russian philosophers, ranked among Russian neo-Kantianism. Overcoming the indicated difficulties, which undoubtedly affect the objective disclosure of the creativity of each representative of Russian neo-Kantianism or thinkers related to them, seems appropriate not only from the standpoint of the history of philosophy, but also for actualizing the heritage of philosophers in the conditions of modern socio-humanitarian pragmatics. Russian neo-Kantianism The author of the article suggests that one of the ways to overcome the ambiguity of the definition of Russian neo-Kantianism in the history of Russian thought may be, firstly, a more detailed consecration of the activities of Russian neo-Kantians in the historical and philosophical literature, and secondly, a comprehensive representation of this direction, including studies of individual personalities and their works. Despite the controversial and polemical nature of the task, its formulation is necessary for the objectivity of the meaning of Russian thought in the global context. (shrink)

One of the most important tasks in each philosophical tradition is to determine the methodological foundations and the target reason for research practice. Russian Russian neo-Kantianism raises several fundamental questions, including the criteria for distinguishing individual systems and the possibility of their integral reconstruction, the identification of the independence of Russian philosophers in overcoming the key contradictions of transcendental idealism, as well as discussions regarding the contribution of Russian neo-Kantians to the history of the development of Russian and European philosophy. (...) No less significant is the problem of uniting Russian neo-Kantianism in the context of the general tradition of neo-Kantianism in its development to the latest trends. The prospect of turning to the heritage of Russian philosophers is largely determined by the design of post-Kantianism and post-Neo-Kantianism. In the works of A.I. Vvedensky, and then B.A. Focht, V.E. Seseman, S.L. Rubinstein, and many others, the transition from German classical idealism in the prism of the specifics of Russian philosophy to the formation of a new understanding of transcendental philosophy and its tasks was marked. In many ways, the proposed solutions were distinguished by originality and obvious independence, but at the same time they were implicitly within the boundaries of the tradition of German neo-Kantian philosophy set by I. Kant. Comparing the latest prospects for the development of neo-Kantian methodology, it can be assumed, not without reason, that Russian neo-Kantianism has largely anticipated the latest trends. Russian neo-Kantians need to reveal the unity of the entire tradition for an objective assessment and subsequent actualization of the heritage of the Russian Neo-Kantians, accompanying this process with a historical and philosophical reconstruction of individual systems of philosophy, but also identifying those perspectives for philosophy that were designated by Russian thinkers. Russian neo-Kantians' problem field of self-determination within the framework of the history of Russian and European philosophy is proposed in the content of the article. Special attention is focused on the unity of methodological tasks and the target reason for the research practices of thinkers who at different stages of their development contributed to the formation of the phenomenon of Russian neo-Kantianism. (shrink)

To mitigate the potentially devastating effects of the COVID-19 pandemic, it is vital to identify psychosocial and moral resources. The care, preservation, protection, and well-being of social communities are attributes of prosocial behavior that can be such a resource. The purpose of the study is to identify the features of prosocial orientation of Russian youth during the COVID-19 pandemic, as well as to identify strategies for prosocial behavior during the COVID-19 pandemic. The sample consisted of 447 people. The study was (...) conducted in May 2020 in the form of an online survey of subjects using Google Forms (“Moral Foundations Questionnaire method” and “Portrait Values Questionnaire”). The research made it possible to establish that Russians were dominated by norms of care, fairness, purity; values of benevolence-universalism, security, and self-direction. During the COVID-19 pandemic, the prosocial orientation of Russians may manifest itself in the following behavioral strategies: proactive prosocial strategy of “caring for others” (true altruism, expressed in forms of volunteering, helping a stranger, and charity despite the risk of contracting a coronavirus infection); egoistic strategy of prosocial behavior “self-care through caring for others” (volunteering based on self-development; helping a stranger to improve your own psychological well-being); conventional prosocial strategy “self-care” (self-isolation and preventive behavior). In the long run, it is necessary to identify personal and environmental resources that allowed people to effectively implement a prosocial self-isolation strategy during the COVID-19 pandemic, as well as various forms of volunteerism. (shrink)

Ch. 1. Filosofskoe osmyslenie kulʹtury -- ch. 2. Problemy mnozhestvennosti kulʹtur.

The article reveals the value and contribution of A.I. Vvedensky in the formation of Russian neo-Kantianism on the example of a systematic and integrated review of his research. The author reveals the significance of A.I. Vvedensky critical methodology for the subsequent development of Russian neo-Kantianism in the first third of the XX century. The method of “logicism” is designated as an integral part of criticism, which consists in the elimination of dogmatic foundations from philosophical discourse. In turn, the critical methodology, (...) understood as a theoretical tool for constructing a holistic picture of the world on the principles of science, serves as the basis for identifying the problems of the correlation of the rational and the irrational. The indicated problem in the works of A.I. Vvedensky becomes the beginning of the formation of Russian neo-Kantianism, which is opposed to dogmatism and religious and philosophical research. Developing a critical methodology, the Russian philosopher turns to the consideration of the role of philosophy in the formation of ideological foundations. The contents of the article consistently reveal the key provisions of the philosophy of A.I. Vvedensky, from raising the question of the methodological foundations of criticism to identifying the specifics of philosophy in relation to scientific disciplines, on the example of experimental psychology, based mainly on empirical methods. In conclusion, the article indicates the prospect of further comprehensive study of the works of A.I. Vvedensky in order to establish a reliable understanding of the development of the national philosophy of thought. (shrink)

Researchers have long suspected that grapheme-color synaesthesia is useful, but research on its utility has so far focused primarily on episodic memory and perceptual discrimination. Here we ask whether it can be harnessed during rule-based Category learning. Participants learned through trial and error to classify grapheme pairs that were organized into categories on the basis of their associated synaesthetic colors. The performance of synaesthetes was similar to non-synaesthetes viewing graphemes that were physically colored in the same way. Specifically, synaesthetes learned (...) to categorize stimuli effectively, they were able to transfer this learning to novel stimuli, and they falsely recognized grapheme-pair foils, all like non-synaesthetes viewing colored graphemes. These findings demonstrate that synaesthesia can be exploited when learning the kind of material taught in many classroom settings. (shrink)

Traditionally, the formulae in modal logic express properties of possible worlds. Prior introduced “egocentric” logics that capture properties of agents rather than of possible worlds. In such a setting, the article proposes the modality “know how to tell apart” and gives a complete logical system describing the interplay between this modality and the knowledge modality. An important contribution of this work is a new matrix-based technique for proving completeness theorems in an egocentric setting.

The article offers a rigorous truth condition for subjunctively conditional statements. The theory is framed in the system of transparent intensional logic and takes connections (especially the cause-Effect relation) as basic. Counterexamples are given to rival theories based on the notion of world similarity.

Traxler, Pickering, and Clifton found that ambiguous sentences are read faster than their unambiguous counterparts. This so-called ambiguity advantage has presented a major challenge to classical theories of human sentence comprehension because its most prominent explanation, in the form of the unrestricted race model, assumes that parsing is non-deterministic. Recently, Swets, Desmet, Clifton, and Ferreira have challenged the URM. They argue that readers strategically underspecify the representation of ambiguous sentences to save time, unless disambiguation is required by task demands. When (...) disambiguation is required, however, readers assign sentences full structure—and Swets et al. provide experimental evidence to this end. On the basis of their findings, they argue against the URM and in favor of a model of task-dependent sentence comprehension. We show through simulations that the Swets et al. data do not constitute evidence for task-dependent parsing because they can be explained by the URM. However, we provide decisive evidence from a German self-paced reading study consistent with Swets et al.'s general claim about task-dependent parsing. Specifically, we show that under certain conditions, ambiguous sentences can be read more slowly than their unambiguous counterparts, suggesting that the parser may create several parses, when required. Finally, we present the first quantitative model of task-driven disambiguation that subsumes the URM, and we show that it can explain both Swets et al.'s results and our findings. (shrink)

The aim of this book is to explore the possibilities and limits of Comenius's greatest and most important work, General Consultation Concerning Restoration of Human Affairs. The humanity of people is not quite right, but not quite lost--that is the foundational anthropological assumption of the Consultation. How does Comenius understand humanity? What are human affairs? What's wrong with them? And the most important question: Can they be somehow corrected, improved, or restored?

Introduction. The article is focused on analyzing the aesthetic aspect of A. Kojève’s philosophy, the ability of his philosophy, from an aesthetic point of view, to clarify a number of key problems of the modern political and cultural environment. The purpose of the study is to determine the epistemological attitude of A. Kojève’s philosophy able to clarify the way in which his philosophy problematizes the current cultural and political reality. Methods. Hermeneutics, comparative analysis and deconstruction are used as research methods. (...) Comparative analysis allows us to demarcate A. Kojève’s own line of reasoning, in the context of aesthetic and epistemological theories, as well as Hegelian themes themselves. Hermeneutics is the central method in the work, since the philosophy of A. Kojeve requires interpretation as an aesthetic theory. Deconstruction, formalized to the status of a method according to P. de Man, allows us to detect inconsistencies, the principle of mutual problematization of Kojeve’s philosophy and the current political and epistemological agenda. Scientific novelty of the research. The standard way of interpreting the work of A. Kojève is to evaluate him as an interpreter of G. Hegel. The author analyzes some meaning of A. Kojève’s philosophy, separate from G. Hegel’s explanation of the text. The novelty lies not only in the fact that A. Kojève’s philosophy is defined as theorizing that goes beyond technical hermeneutics (clear presentation), but also as a specific representation of such theorizing as epistemological aesthetic theory. The latter is a rather rare interpretation of the philosophy of A. Kojeve. This allows us to expand the traditional assumption that post-Hegelian epistemesthetics is the property of an extremely limited number of authors (for example, B. Croce). Moreover, such an interpretation of A. Kojève’s theories is a new element in the emerging trend of considering political issues within the framework of epistemological aesthetics. Results. The specific mode of interpreting G. Hegel, which is carried out by A. Kojève, turns the philosophy of the former into a unique aesthetic project. In this project, the category of aesthetic experience comes to the foreground, indicating the empty, formal nature of any discourse. In this regard, any claim to knowledge of reality, to a correct idea of the subject is replaced by the idea of creating the subject of discourse. Consistent treatment of this idea is symptomatic of the philosophy of A. Kojève. This philosophy is a reflection of those historical changes that gave rise to the culture of “aesthetic rationality”: empty and formal. In A. Kojève’s philosophy, one can see how such a culture of the End of History is, contrary to Hegelian ideas, not the era of the struggle decline, but the era of its strange transformation, a symptom of increasing political violence. Conclusions. A. Kojève’s philosophy is considered not as a utopian political project, but as a problematization of the modern cultural and political sphere. The latter is understood as an indication of the inconsistency of ontological discourses of Truth, the discovery in the very essence of discursive practices of an empty, formal principle, and therefore primarily of interest to aesthetics. The modern era of the End of History and the end of the era of persuasive speech gives an idea of the main political paradox (at least for the philosophy of A. Kojève, and at most for the modern political environment). The era of disappointment in discourse should become an era of refusal to fight for discourses, but it becomes an era of maximizing violence, since it is in a situation of disappointment that discourses can only be supported by force. We move from unconvincing speech to convincing violence, but it is possible to understand the origins and specifics of this transition only by considering A. Kojève’s philosophy in the light of such a discipline as aesthetics. (shrink)

Roman Catholic and Eastern Orthodox theologians claim that the unique event of Christ’s sacrifice on Calvary is present in Eucharistic liturgies. A popular explanatory strategy for this miraculous presence suggests that due to its supernatural character the Eucharist “conquers time,” transcends its boundaries, and allows for temporal coincidence of two chronologically distant events. I discuss the four main approaches within this strategy that can be discovered in contemporary theological writings. The first approach implies a time travel of the Calvary event. (...) The second suggests the time travel of Eucharistic participants. The third eliminates the chronological distance by relocating one of the events into a timeless reality. The fourth assumes multilocation of the event across time. I argue that each of these approaches is untenable on philosophical or theological grounds. (shrink)

In this paper we argue that Aristotle operates with a particular theoretical model in his explanation of animal locomotion, what we call the ‘centralized incoming and outgoing motions’ model. We show how the model accommodates more complex cases of animal motion and how it allows Aristotle to preserve the intuition that animals are self-movers, without jeopardizing his arguments for the eternity of motion and the necessary existence of one eternal unmoved mover in Physics VIII. The CIOM model helps to elucidate (...) Aristotle’s two central yet problematic claims, namely that the soul is the efficient cause of animal motion and that it is the internal supporting-point necessary for animal motion. Moreover, the CIOM model helps us to explain the difference between voluntary, involuntary and non-voluntary motions, and to square Aristotle’s cardiocentrism with his hylomorphism, but also, more generally, it provides an interesting way of thinking about the place of intentionality in the causal structure of the world. (shrink)

Motivated by the problem of finding finite versions of classical incompleteness theorems, we present some conjectures that go beyond NP ≠ coNP. These conjectures formally connect computational complexity with the difficulty of proving some sentences, which means that high computational complexity of a problem associated with a sentence implies that the sentence is not provable in a weak theory, or requires a long proof. Another reason for putting forward these conjectures is that some results in proof complexity seem to be (...) special cases of such general statements and we want to formalize and fully understand these statements. Roughly speaking, we are trying to connect syntactic complexity, by which we mean the complexity of sentences and strengths of the theories in which they are provable, with the semantic concept of complexity of the computational problems represented by these sentences. -/- We have introduced the most fundamental conjectures in our earlier works. Our aim in this article is to present them in a more systematic way, along with several new conjectures, and prove new connections between them and some other statements studied before. (shrink)

We prove an exponential lower bound on the length of cutting plane proofs. The proof uses an extension of a lower bound for monotone circuits to circuits which compute with real numbers and use nondecreasing functions as gates. The latter result is of independent interest, since, in particular, it implies an exponential lower bound for some arithmetic circuits.

The subject of the study is the socio-cultural threats to the information security of Russian citizens associated with ChatGPT technologies (Chat Generative Pre-trained Transformer, a machine-generated text response generator simulating a dialogue). The object of research − evaluation of the ratio of advantages and threats of generative language models based on "machine learning" in modern (2021-2023) scientific literature (journals HAC K1, K2 and Scopus Q1, Q2). The scientific novelty of the research lies in the culturological approach to the analysis of (...) threats to the security of Russian citizens associated with the use of ChatGPT as one of the technologies of "artificial intelligence". The formulation of the problem of the classical Turing test "to distinguish a person from a machine" is characterized as a scholastic abstraction, instead a more correct and productive approach is proposed: a socio-cultural assessment of the value (based on cultural axiology) of new computer technologies. The starting point of the analysis is the determination of socio-cultural value (or, conversely, damage) as a result of the use of generative language models based on machine learning. Further, the contribution and responsibility of various socio-cultural subjects of its creation and application are revealed − user, creator and developer. The result of the application of the proposed approach is the deconstruction of the discourse of the "philosophy of artificial intelligence" in terms of uncritical translation of developer declarations intended for marketing and attracting financing. Hypertrophied perception, precariously balancing on the edge of utopia and dystopia, is assessed as a risk of incorrect identification and ranking of threats to information security. Assumptions about the hypothetical "superweapon of psychological warfare" mask modern incidents of cross-border leakage of confidential data, the risks of being held accountable for publishing deliberately false information and illegal content as a result of using ChatGPT. National security measures are recommended, including restrictive measures and increasing the general civil culture of information security of users, as well as the orientation of domestic developments of solutions of this type on traditional values, socio-cultural identity and interests of Russian citizens. (shrink)

The subject of the article is the philosophical and cultural methodology of digital "virtual reality", comparing the declarations of developers with the practical possibilities and social consequences of using such technologies. The developers presented projects of online digital content services for all five senses using special equipment (glasses, headphones, interactive gloves, joysticks, costumes, printers of smells and tastes, etc.). It was assumed that virtual reality would surpass the reliability of previous multimedia content and interactive computer games, and the persuasiveness and (...) attractiveness of traditional technical means of art and the press. Failure to fulfill these promises has led to significant losses since 2022 for leading companies developing digital virtual reality technologies Meta (recognized by the court as an extremist organization on 03/21/2022, activity is limited in the territory of the Russian Federation), Microsoft HapticLinks, Cave, AlloSphere, Teslasuit, VRealizer. There was a need to assess how and to what extent the methodology used and the predicted capabilities of digital virtual reality were correct. Philosophical and cultural analysis as a research method reveals: the developers of digital virtual reality promised the methodologically impossible, reducing human perception to the "sum" of the external "five senses" out of connection with the "self", inner sensitivity, bodily self-perceptions. A person is only partially amenable to algorithmized digital interaction; a critical barrier to digital virtuality is the socio-cultural identity of society and personality. The novelty of the results of the analysis lies in the conclusion: digital virtual reality in many respects is fundamentally inferior in effectiveness to traditional technical means of sensory and emotional impact and cognition, used both for creative and destructive purposes. In terms of creative potential, digital virtual reality is inferior to the technical means of art, science, education, upbringing, etc., and in terms of destructive capabilities, it is already used in the press and other mass communications technologies for manipulating public and individual consciousness, as well as psychotropic substances that cause addiction. National regulation of the development of digital "virtual reality" is recommended, aimed at protecting and developing the socio-cultural identity of Russian citizens and society, as well as for cognitive and educational purposes. It is recommended to limit the remote use of such developments to trusted domestic Internet services. (shrink)

European Journal of Philosophy, EarlyView.

“Eco-labels” are an increasingly important form of private regulation for sustainability in areas such as carbon emissions, water consumption, ethical sourcing, or organic produce. The growing interest and popularity of eco-labels has also been coupled with growing concerns about their credibility, in part because the standard-setting and conformity assessment practices that eco-labels adopt exhibit striking differences. In this paper, we assess which assurance practices contribute to eco-labels being perceived as better governed, in the eyes of experts as well as the (...) media. Unlike previous studies, which are mostly conceptual, qualitative, or focused on one or few eco-labels, we study a large set of eco-labels, combining data from three different sources. Our findings suggest that experts and media are primarily concerned about “re-assurance” practices, looking for one or preferably multiple layers of “re-assurance” that independent parties are overseeing the eco-label and the firms certified under it. (shrink)

Studie má za cíl představit strukturu Hayekova evolucionismu. Argumentace postupuje v několika krocích: Východiskem je historicko- systematická expozice způsobu, jakým evoluční teorie ovlivnila Hayekovu filosofii, především s ohledem na periodizaci vývoje jeho myšlení a systematické odlišení explanans a explanandum v rámci jeho teorie vědy. Dále je rozebírán způsob, jakým Hayek rozvíjí svoji metodologii vědy. V této souvislosti je argumentováno ve prospěch teze, že Hayekovo pojetí metodologického dualismu je důsledkem ovlivnění evoluční teorií. Zároveň je evoluční teorie představena jako nástroj vysvětlení, konkrétně (...) pak tzv. vysvětlení vzorce. Následně je představeno Hayekovo pojetí společnosti v kontextu kulturní evoluce. Společnost je interpretována jako řád jednání a je kladen důraz na Hayekovo vnímání společnosti jako řádu vyvíjejícího se společně s lidskou myslí. Na základě těchto předpokladů je v poslední části rozvinuto Hayekovo pojetí mysli. Toto pojetí vychází z konekcionistické pozice. Dále argumentuji proti tradičnímu pohledu na Hayekovu filosofii jako rozvíjení Kantovy filosofie. Závěr rekapituluje základní body Hayekova evolucionismu. (shrink)

Článek se zabývá způsobem, jakým vnímá vztah vědecké metody a demokracie Karl Popper. Toto sepětí je jedním ze základních atributů Popperova myšlení. Pro jeho pochopení je třeba zasadit Poppera do historického kontextu vývoje liberálního myšlení a poukázat na možné souvislosti se Schumpeterovou redefinicí demokracie. Výchozím bodem je však interpretace základních episte- mologických předpokladů Popperova myšlení - konceptů provizornosti vědeckého poznání a ratio negativa. Primárním cílem článku je kontextualizace těchto předpokladů s politologickými a sociologickými důsledky. Ty lze spatřovat nejen s odmítnutím (...) positivismu a esencialismu, ale také v Popperově preferenci volebních a stranických systémů. Na závěr je rozpracována problematika kritického racionalismu, hodnot a otevřené společnosti na základě možných námitek vůči Popperově teorii. (shrink)

We give an exponential lower bound on the number of proof-lines in intuitionistic propositional logic, IL, axiomatised in the usual Frege-style fashion; i.e., we give an example of IL-tautologies A1,A2,… s.t. every IL-proof of Ai must have a number of proof-lines exponential in terms of the size of Ai. We show that the results do not apply to the system of classical logic and we obtain an exponential speed-up between classical and intuitionistic logic.

Aristotle's notion of experience plays an important role in his epistemology as the link between perception and memory on the one side, and higher cognitive capacities on the other side. However, Aristotle does not say much about it, and what he does say seems inconsistent. Notably, some passages suggest that it is a non-rational capacity, others that it is a rational capacity and that it provides the principles of science. This paper presents a unitary account of experience. It explains how (...) experience grows from perception and memory into a rational capacity, and in what way it provides the principles. (shrink)

This essay sheds additional light on the biographies and fates of Ayn Rand’s closest relatives in the Soviet Union and abroad after young Alissa Rosenbaum left the “country of workers and peasants” in 1926 for the pursuit of a new life in the United States. Previously unknown facets of her relatives’ lives were intertwined with the complex and often tragic historical events of the first half of the twentieth century. Among these relatives are victims of the German blockade of Leningrad, (...) a music teacher, a European bacteriologist, a doctor who was twice a refugee, and a Soviet Medical Service Corps officer. (shrink)

The paper gives a survey of results related to a problem of automatic recognizing important properties of non-classical logics.

Khoussainov and Nerode [14] posed various open questions on model-theoretic properties of automatic structures. In this work we answer some of these questions by showing the following results: There is an uncountably categorical but not countably categorical theory for which only the prime model is automatic; There are complete theories with exactly 3,4,5,…3,4,5,… countable models, respectively, and every countable model is automatic; There is a complete theory for which exactly 2 models have an automatic presentation; If LOGSPACE=PLOGSPACE=P then there is (...) an uncountably categorical but not countably categorical theory for which the prime model does not have an automatic presentation but all the other countable models are automatic; There is a complete theory with countably many countable models for which the saturated model has an automatic presentation but the prime model does not have one. (shrink)

We study the following open question in computable model theory: does there exist a structure of computable dimension two which is the prime model of its first-order theory? We construct an example of such a structure by coding a certain family of c.e. sets with exactly two one-to-one computable enumerations into a directed graph. We also show that there are examples of such structures in the classes of undirected graphs, partial orders, lattices, and integral domains.