Critical thinking is a reasoned thought that helps us to decide what to believe, think, or do. It is not valued only the final decision, but also the process of thought that has been followed. It has, therefore, an analytical and an evaluative part (Ayala, García and Santiuste, 2001).

There are numerous studies on this concept (Lipman, 1987; Garrison, Anderson and Archer, 2001; Pithers and Soden, 2000) and it is common to find approaches to it in the field of education with different methodologies, in which they aim to assess its relevance in this area (Callister and Burbules, 2000). As a result, critical thinking in education is challenged and there are some uncertainties about its inherent process as the definition of objectives, the role of educators, and the evaluation of results.

Critical thought makes possible the development of a right judgment based on criteria, being self-correcting and context sensitive (Lipman, 2016), so determine the key elements for their specific training and their evaluation is a complex process. The assessment of critical thinking has great limitations because it is multiple constructs from which short-term conclusions cannot be drawn. However, despite the difficulty this entails, it is essential to reveal the purposes and values of educational actions and discuss constantly their validity (Jover, Gozálvez and Prieto, 2017), something that is possible thanks to questioning, deliberation, and evaluation.

Setting clear goals for educating critical thought is a difficult task, which outlines general lines. For that, it is still necessary to define more precisely the most effective current methodological actions. For this, it is necessary to evaluate the methods applied, values the achievement or not of objectives, and apply corrective action.

Educators should conceive the education of critical thought as an end, not as a means because this ability frees the students of impulsive actions and it enables them to achieve future objectives (Dewey, 1993). The main task of educators is to provide students with the necessary tools to build their own thinking: argued, coherent, and in line with values such as respect, solidarity, and acceptance of differences. In this way, by dialog and active listening, students will be capable of forming a thought with which they feel identified. As Siegel (1995) says, argumentation and education are connected, and educators have a moral responsibility to educate in rationality. In this sense, it is necessary not to set limits and not to fall into conformism when reflecting critically on different aspects. In the words of Ibáñez-Martín (2010, p. 17), «(in education) to think that the solution is to avoid everything essentially debatably, it is to go to a way that does lead us nowhere». The correct development of critical thinking allows students to develop self-knowledge that will facilitate the understanding of themselves and their close context.

The main objective of this paper is to analyze the possibilities of teachers to develop critical thought at school and define what objectives they consider essentials to do this. For all these reasons, we propose a series of overall objectives that teachers of secondary education should adapt and apply in different educational contexts. It could be the first step to create a new program of educational intervention. For its configuration we propose a model of character education, seeking a balance between different levels of the human being: intellectual, civic, moral, or affective (Jubilee Centre for Character and Virtues, 2017). Thus, we take as reference variables such as: adopt the same intellectual standards at the individual and social level, develop an affective and empathetic plane, reflect from different logical approaches or be self-critical (Ayala, et.al, 2001).

An analytical method will be used to achieve the objective. For that, first, a study of the concept and its different elements is carried out, and we will apply the technique of the analysis of sources to contextualize which elements should be considered objectives in the educational process and why. In addition, we do interviews with at least 30 teachers from different parts of Spain. It may be conducted to assess, through a basic qualitative analysis (with the Atlas.ti program), which concepts they consider most important when setting goals to develop in the classroom. This method is relevant to European discourse space because we show the possibility to develop critical thought by a character education model. This model is essential in European educational discussion because it is one of the most important models of moral education that develop the best of the human being. Character education responds to the demands of society, so it is flexible, and it searches for common and minimum values. Moreover, the role of the teachers in this educational intervention is important because they take control of what they consider educational goals.

We expect to find that the teachers agree that there are some minimum values (Bárcena, Gil and Jover, 1999) that must be transmitted between generations. However, teachers should also facilitate their students to develop their own critical sense, to promote social values that foster well-being, justice, and social equity. The objective is to transform education into an instrument of society, which we understand as critical or political pedagogy (Ibáñez-Martín, 2010). Therefore, in general terms and from the theoretical study of the construct, some objectives that can be raised for teaching practice are: 1. Respect the mature development of the students. 2. Show logical coherence between thought and action. 3. Build strong arguments for problem-solving. 4. To work in a well-balanced way the cognitive, affective, moral, and instrumental plane. 5. Evaluate moral values not only from conceptual knowledge but from the action. Educating critical thinking is educating people to choose freely the values they consider most appropriate considering the existence of some minimum values. In this way, education allows people to develop the appropriate aptitude and skills that allow them to deliberate and choose correctly in different situations that life raises for them.

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