INTRODUCTION

Thinking about curriculum is thinking about what truly holds value for life. This statement, although it may seem abstract and simplistic, encapsulates much of the analysis, ultimately, of many of the reflections regarding the concept of curriculum. Thinking about it, from various aspects and perspectives, is always thinking about people, both individually and collectively, about their lives, their daily routines, their aspirations, their struggles, and their place in the world. It also involves thinking about which approaches, reflections, and experiences will truly have such meaning for themselves that they will shape, inspire, move, complement, and transform them. This is why, in summary, thinking about the curriculum is thinking about what holds meaning for life.

This is in spite of the fact that, as a territory of dispute between different conceptions, reflecting on the curriculum implies reflecting on the lives of those who teach and those who learn, with ramifications regarding how teaching, learning, and assessment take place, based on declared and recognized or hidden objectives (^{Arroyo, 2013}). Of all the possible implications and ramifications arising from the topic, it becomes evident early in the journey of inquiry and reflection that the search for the meanings of the curriculum extends far beyond the analysis of content prescriptions, sequenced by age group, cycles, and educational levels, which are ordinarily also referred to as the curriculum.

If we draw on the curriculum when analyzed and tensioned from the perspective of ideology and power (^{Apple, 2006}), on the possibility of offering an alternative to centralized curricular policies (^{Lopes and Macedo, 2021}), on the view of the curriculum as specialized knowledge (^{Young, 2014}), on the curriculum as a space for cultural production (^{Macedo, 2006}), on the critique of the reification of knowledge (^{Costa and Lopes, 2022}), and on the curriculum as identity (^{Silva, 1999}) — to name just a few of the widely cited studies on curricular policies in Brazil — there is already much to explore when seeking to add and contribute through further research and studies, so that this richness and complexity regarding the curriculum take root in schools and fulfill the fundamental objective of every researcher, however utopian it may seem: to improve the world (^{Lopes and Borges, 2015}).

In this systematic review study, the focus was directed toward investigating the curriculum in early childhood education, the first stage of Brazilian basic education (^{Brasil, 1996}). Studies on the curriculum at this stage of education soon reveal that, in addition to the debates provoked by the curriculum theme itself, disputes over what should or should not constitute the early childhood education curriculum are also profuse (^{Alves and Fialho, 2019}).

Observing the tensions that the topic already entails, the peculiarities of early childhood education — conflicting between caring, assisting, and educating, crossed by a legacy of welfare policies, and still permeated by societal and educational pressures for early pre-literacy and schooling — it is noted that debates on the curriculum at this stage of education undoubtedly offer a big challenge to researchers and education professionals.

In light of this scenario and the perspectives that have been cautiously outlined, the objective of this systematic review study was established. It sought to investigate, through international and national databases, the answer to the following question: how has the curriculum of early childhood education been problematized by Brazilian and international researchers? To compose the study, initially, some remarks will be made on the concept of curriculum and the historical contexts related to it, even though it is not possible to define it due to its polysemic nature and because it has layers of complexity that cannot be encompassed in a single concept. Subsequently, the methodology used to select the articles that constitute the review study will be described, and, finally, the results will be presented in dialogue with the texts analyzed.

BRIEF HISTORICAL CONTEXT AND NOTES ON THE CURRICULUM

Certainly, all curriculum scholars agree with Young when he declares that he is convinced there is no more crucial educational issue than the curriculum (2014). Academic production in the field has also supported this statement and highlighted, as pointed out by ^{Macedo (2006)}, the intensification of research on curricular policies in Brazil, no longer reliant on foreign studies, particularly from the United States and the United Kingdom, although, as the author also notes, researchers continue to dialogue extensively with these texts.

As Young and Macedo also noted a hundred years ago, Dewey emphasized that curricular experiences went beyond written plans and valued the child's experience as the starting point for the "subjects of study" (^{Dewey, 1965}, p. 48). He also inspired some, such as William Pinar, a reconceptualist theorist who, as the term itself suggests, sought to bring new concepts to curriculum studies; and opposed others, like his contemporary often cited for his opposing views, Ralph Tyler, who held a technicist and linear perspective on educational studies (^{Silva, 2013}).

The influence of Dewey, as well as the widespread presence of uncritical and traditional educational trends, did not withstand the second half of the 20^th century. By this time, critiques of capitalist society included in the debate, as expected, a critical analysis of the political control over education system, and of the technicist curricula inspired by the principles of scientific management (^{Silva, 2006}). From the critique to society and its institutions, the school became a central focus, with particular emphasis on the analysis of curriculum conceptualization and policy.

In this context, from the second half of the 20^th century, after two world wars, a certain pedagogical optimism that had previously been perceived gave way to radical criticism (^{Gadotti, 2003}), and studies in the field of curriculum followed the history of pedagogical movements. From the perspective of the French philosopher Louis Althusser (1969), the school was seen as part of the ideological state apparatus, while sociologists Pierre Bourdieu and Jean Claude Passeron (1970), also French, viewed it as a reproducer of the social structure, and with Claude ^{Baudelot and Roger Establet (1971)}, it was understood as a dualistic school oriented by the interests of capital (^{Silva, 1999}; ^{Gadotti, 2003}; ^{Silva, 2006}).

Although the authors mentioned above, who introduced critical concepts into the field of curriculum studies, had distinct theoretical foundations and wrote from different contexts, it can be inferred, as ^{Lopes and Macedo (2011)} point out, that their theories and worldviews converge in the way they relate knowledge to human interests, class hierarchy, power distribution in society, and ideology. Critical theories question what is understood as knowledge and what counts as school knowledge, not focusing solely on a pedagogical dispute, but also including a political and social struggle, of which the school is a part.

From this first rupture brought by critical theories to traditional education theories, which focused on the technicist, linear, and pretentiously programmable aspects of teaching, other theories emerged in this scenario, adding to the denunciation of the politically reproductive nature of schools, the possibilities of conflict, counter-hegemonic struggle and resistance (^{Gadotti, 2003}).

Exponents of theoretical productions that incorporated the concepts of conflict and resistance into critical theories, well-known in curriculum studies, include Henry Giroux, with his theory of resistance and radical pedagogy; Michael Apple, with his book Education and Power, which more distinctly presents the possibility of resistance as a concept; and Paulo Freire, with his pedagogy of the oppressed (^{Silva, 1999}; ^{Gadotti, 2003}; ^{Silva, 2006}).

It is well known that Paulo Freire was not a curriculum theorist; however, the problematization of his pedagogy closely resembles or aligns with the approaches of curriculum studies. The same can be said of other critical theorists previously mentioned (^{Silva, 1999}; ^{Gadotti, 2003}). Freire, widely regarded as one of the greatest educators of the 20^th century, has had his main work, Pedagogy of the Oppressed, translated into numerous languages. Although he was not a theorist in the field of curriculum studies, it is well known that many researchers and theorists from curricular perspectives have been influenced by his work over time (^{Silva, 1999}).

Traditionally, the study of critical theories is followed by the study of post-critical theories. This term is used to characterize theories that challenge the assumptions of critical theories, which are notably influenced by Marxism, the Frankfurt School, and discussions on the relationships between curriculum, power, and ideology. However, even though curriculum theories are didactically presented and studied from a linear temporal perspective, it is a misconception to interpret this as an evolutionary process — as if traditional theories had evolved into critical theories and then progressed to post-critical theories, as discussed by ^{Lopes (2013)}. Thus, postmodernism does not represent a linear succession to modernism but rather a departure from it.

It is important to emphasize, however, along with ^{Maria Aparecida Silva (2006)}, that the historical relationships between curriculum, the world of work, power, ideology, and cultural hegemony have remained a crucial step toward the development of curricular proposals that are more responsive to the demands of human emancipation.

For the postmodern perspective, which marks the end of critical pedagogy and the birth of post-critical pedagogy, it is not only the curriculum that is criticized, it is the critical theory of the curriculum itself that is placed under suspicion, since the critical theorization of education and the curriculum itself is based on the principles of the great narratives of modernity (^{Silva, 1999}).

Despite the imprecision of the expression "post-critical theories", it is highlighted that it is sought to name a set of theories that problematize the postmodern scenario, and includes post-structural, post-colonial, post-modern, post-foundational and post-Marxist studies (^{Lopes, 2013}). Within post-critical theory, three key terms are considered fundamental: identity, subjectivity, and meaning. For post-critical studies, identity and difference only exist through the presence of the other. Therefore, the curriculum can only be understood through the meaning that each individual attributes to it (^{Silva, 2013}).

Tomaz Tadeu da Silva, in his book Documentos de Identidade: uma introdução às teorias do currículo [Identity documents: an introduction to curriculum theories], listed some key terms from each of these major groups of curriculum studies, the main categories of theories, according to the concepts they emphasize. This helps to clarify their key differences:

Traditional theories: teaching, learning, assessment, methodology, didactics, organization, planning, objectives, efficiency. Critical theories: ideology, cultural and social reproduction, power, social class, capitalism, social relations of production, awareness, emancipation and liberation, hidden curriculum, resistance. Post-critical theories: identity, otherness, difference/ subjectivity, meaning and discourse, knowledge-power, representation, culture/ gender, race, ethnicity, sexuality/ multiculturalism. (1999, p. 17, author's emphasis).

Despite the instability of the postmodern scenario, the decline of grand narratives and foundations, societal transformations, as well as the overlapping of times, contexts, theories, and meanings, a political curriculum project is not necessarily condemned to hopelessness and impossibility. The dubious possibility of giving meaning to postmodernity does not prevent a search for such meaning. "We can dedicate ourselves to it, without losing sight of how unstable, provisional and precarious it is and, therefore, how powerful it is: it is open to being constantly remade in unpredictable ways" (^{Lopes, 2013}, p. 21).

METODOLOGY

The systematic literature review is a research technique used to evaluate and synthesize the literary work that has been published on a given topic (^{Carvalho and Ximenes, 2022}). "The literature review conducted in this way allows for the replicability of the study and promotes the cumulative nature of scientific knowledge" (^{Meira, 2020}, p. 6).

Review studies are important and contribute to deepening and systematizing the vast amount of scientific knowledge produced by researchers. The aim of synthesizing research is to bring together, in a single work, the results of various studies (Figueiredo Filho et al., 2014, apud^{Meira, 2020}), an action that optimizes, especially for the reader, access to up-to-date and scientific knowledge on a specific topic in an objective and efficient manner.

The steps that constituted this bibliographic review work correspond to the basic steps of a systematic review as presented in the study by ^{Mendes and Pereira (2020)}, which appear in all the works analyzed by these authors. These steps are: objective and research question; search for works; selection of studies; analysis of productions; presentation of the systematic review.

The objective of this systematic review research was to understand how the topic of the early childhood education curriculum is being problematized among Brazilian and international researchers. Based on this initial delimitation, the first stage of this review was defined.

For the bibliographic survey, the second stage to be developed, searches were conducted for peer-reviewed scientific articles in two international databases, Scopus and Education Resources Information Center (ERIC), using the English keywords "childhood education" and "curriculum," connected by the boolean operator "AND". The aim of this first stage of the search, using English keywords and conducted in international databases, was to map and understand the work of researchers from various countries on the early childhood education curriculum over the past five years.

Subsequently, a search was conducted in the Coordination for the Improvement of Higher Education Personnel (CAPES) Periodicals Portal using the same keywords, but in Portuguese, and the same boolean operator. This time, the objective was to add a significant contribution from Brazilian researchers, not wrongly assuming that the CAPES library is limited to Brazilian productions, but rather considering that the volume of Brazilian works resulting from this search would be more substantial.

In the third stage, the selection of studies, it was observed that, from the collection of articles gathered through the three searches conducted in the aforementioned databases and in the CAPES library, which will be further detailed in the results section, many articles were discarded for not fitting within the scope of the research. For example, many of the articles from the initial searches dealt with topics such as the COVID-19 pandemic or very specific areas of knowledge, such as robotics, the environment, the use of technologies, video games, spirituality, etc., as well as other themes that were not significantly related to the question the research aimed to address. This narrowing for analysis was necessary because not all material is suitable for inclusion in a sample, and, in this case, it is better to reduce the universe itself (Bardin, 2011).

To systematize the bibliographic review, a quantitative approach was initially used, since the initial stage of the research consisted of quantifying all the files resulting from the first search, which was carried out following the steps of applying keywords, delimiting the period covered to the years between 2018 and 2023, and applying peer review filters, limited to scientific articles, with full papers available in the database or library.

After this initial quantitative phase, a qualitative stage of research ensued in which, firstly, all the titles of the articles collected were analyzed and, after discarding the articles whose titles did not appear to belong to the scope of the research, the abstracts of these first selected articles were read. Still in this third stage of article selection, after reading the abstracts, some other works were also excluded, for the same reason of not having any connection with the research problem.

For the start of the fourth stage of the research, analysis of the productions, it was first necessary to refine the search until the collection of selected articles for the study provided the necessary material to answer the research objective. To better clarify this filtering process, the table below presents the description of the searches conducted, the keywords used, results, and selected articles.

As shown in the Chart 1, the initial search for articles, based on the application of keywords, operators, and filters, resulted in 590 articles. After reading the titles and abstracts of all the texts from this first compilation, those that were unrelated to the topic under analysis and those that were duplicates (appearing in results from more than one database) were excluded. During this second evaluation, 79 studies were selected. Following this, after careful reading of the full texts, a few more articles were discarded as they still appeared in the list but were not directly related to the research problem.

Once the stages were completed, the set of documents to be submitted to analysis, that is, the research corpus (Bardin, 2011), consisted of 30 peer-reviewed scientific articles, both national and international, addressing the study topic and published between 2018 and 2023. These articles are detailed below in Charts 2, 3 and 4, separated by the researched database.

To develop the fourth stage of the research, which consisted of the analysis of the productions, we sought to rigorously identify points of convergence between the articles, creating a list of topics, reflections, and main conclusions of each work. Afterwards, these excerpts were grouped by semantic approximation, thus creating four categories, which emerged after analogical and progressive classification of the elements, configuring a type of categorization by "collection", with the conceptual title of each category being defined only at the end of the operation (Bardin, 2011).

DISCUSSSIONS

Finally, after the methodological design of this systematic review, the fifth and final stage of the research was reached, which consisted of the presentation of the systematic review, which is shown in the form of four conceptual categories: curriculum and early childhood education; the lived curriculum; early childhood education and the BNCC-EI; the challenge of accepting childhood times.

FINAL CONSIDERATIONS

Although the owl is the symbol of pedagogy, reflecting on education goes beyond the possibilities of philosophy. If the owl of Minerva¹ always takes flight at dusk and, analogously, philosophy always reflects on what has already happened, thinking about education is a more dynamic, open process with many possibilities. Although reflecting on education undoubtedly involves thinking about the history of human education, this reflection is not fatalistic. On the contrary, it opens space for other alternatives, creates new expectations, provokes, and invites involvement and doing things differently while there is still time. The time to weave something new is the present, until the twilight of an entire generation of education professionals arrives, a time when there will no longer be any possibility of changing the course of history.

From this perspective, upon completing this systematic review, which aimed to understand how the early childhood education curriculum has been problematized, it becomes clear that there is much to consider and reflect upon regarding the various factors that shape the uniqueness of early childhood education. However, beyond bringing multiple aspects of this issue to the forefront, the insights emerging from all the studies conducted also highlight possibilities for resistance, action, and transformation.

The categorization of the 30 articles that comprised the corpus of this study provided valuable diagnostic possibilities regarding the various elements that constitute this mosaic of deeply rooted pedagogical traditions, political interferences and influences, and the need for more critical reflections on the process — both at the macro and micro levels — referred to, albeit not simplistically, as the early childhood education curriculum.

The convergence of ideas among the authors of the sampled articles on the early childhood education curriculum has provided highly relevant and significant contributions to the field. The similarity of the identified issues, their aggravating factors, and the persistence of some of these challenges — which have long confronted teachers and researchers throughout the history of early childhood education as a mandatory stage in both Brazilian and international educational systems — serves as a solid foundation and, in itself, constitutes a rich, compelling, and representative body of material reflecting the reality of early childhood education in both national and global contexts.

The alternatives for resistance and confrontation that emerged from the texts were also abundant. Just as the reference to the owl of Minerva in philosophy at the beginning of this conclusion and its distinction from reflections on education, thinking about the complexity of the educational processes, permeated by lives, historical legacies, and diverse social realities, does not mean bringing it all together in a fatalistic scenario. On the contrary, analyzing the various elements that underscore this complexity means creating possibilities and forging tools for resistance and transformation.