Antithesis:Alternative:Process:Repetition

According to Aristotle, a Greek philosopher and his successors like Kant:
"To each thesis there must exist an antithesis or antinemy - a proposition that every valid thought must have an idea. An idea is an antithesis (e.g. rainy day [which could be thesis]) and not rainy day ([which is a possible opposite, its negation... antithesis of "rainy day"]) - fact of the weather. ([Fact is synthesis - resulting process, a conflict that arises between thesis and antithesis. No thesis can exist without an antithesis. Existence and non-existence results in actuality... of history. So, history is synthesis of existence and non-existence... Each stage in this process, the synthesis, the cycle of dialectical change becomes a new thesis... and so the process goes.) Every idea or thought has its opposite. All valid propositions or ideas contain their own negations... Key of the dialectics... - every idea, a state of affairs, contains its own opposites."

- THE DIALECTICAL METHOD OF REASONING: September 23, 2010 (an online lecture "GWF HEGEL (3): THE DIALECTICAL METHOD OF REASONING": )