In Alain Badiou's opinion, "truth" does not originate from philosophy, but emerges in the four fields we have known so far: science, politics, art, and love, which are the conditions of philosophy. He refers to the "status" in the four fields, and in his opinion, the "void" in the current status, and consequently, the occurrence of the "event" leads to the creation of truth. According to him, "subjects" in each of the fields complement the event with "fidelity" to it. In relation to each of the four fields mentioned, Badiou gives examples of cases of occurring events and provides examples of subjectivity in each of them. For example, in connection with art, he speaks of theatre, poetry, painting, cinema, dance, novel, music, sculpture, and the occurrence of events in them. According to him, when a text is staged by actors and directed by a person, an event is formed at the same moment, but if the viewer decides to react positively to the new event and accept it, they actually become the subject. Then the truth occurs and the event relates to the world around it through the viewer.
But what is the status of these interdisciplinary fields of art? Do Badiou's definitions of truth, subject, and event apply in the field of media, especially in modern advertising? In this article, we intend to deal with an aspect of environmental advertising that needs to be performed by the audience through the interaction or participation of the audience to complete and convey the message, and therefore  parallels Badiou's subjectivity of truth. The subject is very important in Badiou's intellectual system; because in all fields that can originate the truth (science, politics, art and love), the subjects are the factors that  ultimately create truth by their actions, through their fidelity to events. The importance of human subjects in the fields of truth creation doubles the importance of modern interactive and participatory media. These modern media, and especially the interactive-participatory advertising, due to involving the audience in the text domain, put the audience into a tow-way communication, and unlike traditional advertising, leave the completion of the advertising message to the audience.
But, is any type of interactive or participatory advertising the scene of occurrence of the event? Does the audience become the subject by their performance, or become the subject when they decide not to participate in completing the advertising message? And how do truths and events become possible in interactive-participatory advertising? These are the questions that we will answer in this research. This study is qualitative and has been done by descriptive content analysis. Study samples have been purposefully selected from commercial and non-commercial environmental advertising according to the characteristics of interactive-participatory advertising. In this research, first, the characteristics of key concepts in Badiou's discourse, including truth, event, and subject, also the truth of art from Badiou's point of view are explained. Then, the characteristics of interactive and participatory advertising are presented, and finally in the main discussion section of the research, the conditions of truth production from Badiou's perspective in interactive-participatory environmental advertising, are examined.
Overall, in the section of explaining key concepts in Badiou's discourse, the characteristics of event, subject and truth are expressed. Characteristics of the event include: 1. Unpredictability 2. Creation of splits in the cognition of the status 3. Existence of actions, rules, and customs outside of the status 4. Creation of new rules and meaning, and 5. A real change. Characteristics of the subject include: 1. Announcing the occurrence of the event 2. Fidelity to the event 3. Exploring the consequences of the event, and 4. Changing the structure of the status in accordance with the laws of the event. The characteristics of the truth include: 1. Novel and innovative and linked to creativity 2. Comprehensiveness 3. The result of the action of the loyal ones, and 4. Having performative feature. In addition, in this study, in the section of interactive-participatory advertising, we distinguished between two types of interactive advertising and participatory advertising according to the factor of using computer-based and digital interfaces or not. Consequently, if a computer-based interface is used in advertising and through it, the audience communicates with the advertisement, it is interactive advertising, and if this communication takes place without the intervention of a computer-based interface, it is participatory advertising.
According to the studies and matching the characteristics of the subject, event and truth with the study samples in the research, it seems that the advertising message in interactive-participatory environmental advertising can have the characteristics of the event as a trace of the event and interactive-participatory environmental advertising can be a new body. It also seems that the acceptance of the advertising message in the interactive-participatory environmental advertising can be a kind of announcement of the event by the audience and fidelity to the event depends on changing the subject's behaviour towards the advertising message. Sometimes the audience, in accordance with the consequences of the event, transcends and changes other aspects of their lifestyle, which translates into the exploration of the consequences of the event. And also the change in the structure of the status in accordance with the rules of the event can be the same behaviour that emerges from the subject after receiving the message; and this behaviour emerges with a different structure from the existing structure and a real change occurs. Ultimately, it seems that what changes the subject's behaviour in this type of advertising actually interrupts the repetition process and creates a new truth. The subject is placed in a position that leads to a change in their behaviour, and this change in behaviour occurs as the result of a change in the usual structure. It should be noted that the truth is comprehensive in this type of advertising and any subject can create it. Because, basically, environmental issues and concerns have a general audience, and as a result, the behaviour of loyal subjects can be achieved by any other subject and create truth.
In addition, the research findings indicate that if interactive-participatory advertising contains messages that the result of holding on to them creates splits in the current status, the event occurs and consequently, if the subjects accept the event and in accordance with the rules of the event, express any behaviour with the purpose of changing the current status, the truth is created. In fact, according to Badiou, it can be concluded that those types of advertising that, in addition to promoting consumerism, break the rules and regulations of governments, are considered real advertising, or advertisements that sometimes encourage the audience not to consume industrial products and consumerism. Hence those types of interactive-participatory advertising that promote cultural concerns that are overlooked by economic policies are real advertising. Unlike the economic policies of governments, Interactive-participatory environmental advertising promotes the culture that encourages the audience not to consume industrial products.
Also, due to the universality of truth in Badiou's thought, the subjects of this type of advertising are also general, and any human in confrontation of the event of advertising, can help spread the truth as much as possible, ‌since environmental issues are related to all parts of a society. While in other types of ads, certain audiences may be targeted for receiving the message. Another important issue in relation to the subjects of interactive-participatory environmental advertising from the perspective of Alain Badiou's discourse is fidelity to the event and faithful actions. In Badiou's thought, the creation of truth depends on the performance of an action by a loyal subject. On the other hand, sometimes in interactive-participatory environmental advertising, the product becomes a medium for advertising, and incidentally, the advertising message encourages the audience not to consume the product. Here the audience is put to the test and is considered a loyal subject only when they refuse to consume the products while having access to them, to protect the environment. This is the only situation where the opportunity to use the product is given to audience for their comfortability, but the advertisements ask them not to do so. In fact, the subjects of environmental advertising are the real subjects who move against the current of consumerism in the contemporary world.