Because it carries the connotation of collaboration and mutual respect – and thus offers a guidepost to inter-personal and inter-societal concord and peace. The term is also very important philosophically. The word “dialogue” comes from the Greek and is composed of two parts: “dia” and “logos”. Logos means something like reason, meaning, and also (simply) word. Dia means “in-between” or “betwixt-and-between”. Hence dia-logue means that reason or meaning is not the monopoly of one party but emerges in the intercourse or communication between parties or agents. The logos here is a shared logos and depends crucially on the participation of several or many people.
Viewed from this angle, the turn to dialogue can be seen as part and parcel of the so-called “linguistic turn” or “turn to language” which is a central feature of the twentieth century. The linguistic turn involved a turning away from a philosophy concentrated on the singular “I”, on ego consciousness, on what Descartes called the “cogito” (I think). His formula “ego cogito ergo sum” (I think therefore I am) implied that reality could be known by the thinking ego alone – without any need to refer to other people. In large measure, Western philosophy from Descartes to Kant was a philosophy without language and without communication. Truth could be established unilaterally by the thinking ego.
During the twentieth century, many philosophers contributed to challenging and overturning this kind of unilateralism. Ludwig Wittgenstein is famous for claiming that truth, reason, and meaning are necessarily the corollaries of a functioning “language game”. However, Wittgenstein did not specifically elaborate a theory of dialogue. The basic building blocks in this direction were provided by various Continental thinkers affiliated with phenomenology and existentialism. Martin Heidegger stressed the crucial role of language in human knowledge and understanding and laid the groundwork for a properly dialogical kind of interaction.
His contemporary Karl Jaspers developed a theory of existential communication as a precondition for human self-understanding. At the same time, Martin Buber formulated a philosophy and even a theology of the “in-between” anchored in the communicative relation between “I and Thou”. Heidegger’s student Hans-Georg Gadamer can be called the quintessential philosopher of dialogue because of his insistence that every inter-personal encounter and every interpretation of texts (hermeneutics) depends on a dialogue where participants are willing to transgress their self-centeredness in the direction of a “fusion of horizons”.
A similar approach was followed by Gabriel Marcel and Paul Ricoeur in France. All these philosophical or intellectual initiatives conspired to call into question the Cartesian cogito and the traditional Western reliance on unilateralism. Unfortunately, it takes considerable time to translate intellectual insights into political praxis. Hence dialogue today is still struggling to make a dent in political monologues and the resulting “clashes” of societies and peoples.