Here is how the dialectic works in everyday life:
People get together for an informal social event. The goal among most of them is to just have an enjoyable conversation. However, often the conversation turns into intense arguments/discussions about a topic involving politics, religion, philosophy, or other random subjects. The conflicting ideas are expressed passionately, often with total conviction and even enjoyment.
Everyone acts as if they believe they are totally right, although each one knows, unconsciously or consciously, that they are probably wrong, or at least partly wrong.
In, say, twenty years, even they, themselves, may disagree with some of the ideas that they so passionately supported. But at the same time, each one feels, unconsciously or consciously, that there is truth out there, and as history moves on, the truth of the topics debated will become clearer and clearer – although perhaps never absolutely clear and true.
Their faith, unconscious or conscious, is that through free and open discussion, between people with an authentic desire for truth, they will come closer and closer to absolute truth.
So, here’s what they often do — consciously or unconsciously:
One person expresses an idea (the thesis). The other people listen and understand the idea. Then another person expresses a criticism of the idea or an contradictory idea (the anti-thesis). Then through continued discussion back and forth, they tentatively (and sociably) agree on combination of the original idea and it’s opposite (the synthesis). This process goes on numerous times throughout the evening, and everyone (hopefully) learns a little, has their own ideas influenced a little, and inches towards absolute truth a little.
And this is how the world turns.