The history of dialectics is as long as the history of mankind's consciousness of its thought.
Early figures were
Heraclitus and Lao Tzu.
Lao Tzu's
Tao Te Ching is available on this site
Other thinkers on this site who are relevant to this topic are:
Heraclitus,
Plato,
Fichte,
Kant,
Hegel,
Marx, Engels, Frankfurt School,
Althusser,
Lukacs, Sartre,
You could also explore the notion of totality.
Totality
Other resources:
Reading guide to Adorno's Negative Dialectics