Left and right are the two sides of a coin just like right & wrong. The existence of one means existence of other. In Politics also, there are two sides opposing each other. Politics emerged as soon as Kings start to form & rule states. They formed councils to guide & maintain power. Since the council was to help the king in his rule it favors establishment whereas the public & its representative sees the ruling as exploitative and thus tries to challenge the establishment.
From the very first days of mankind to till date two laws remain more or less unchanged – who hold the power, tries to maintain it and the person who is being ruled is always unsatisfied. There can be a momentary deviation from these laws –masses can feel satisfied relatively to their earlier time but the satisfaction will not last or a ruler might accept to dilute his power from the fear of losing it completely. It is these laws which form the Left & Right views in politics.