Heraclitus of Ephesus, a Greek philosopher active around 500 BC, proposed the idea of flux and the concept of Logos in his writings. He famously asserted that change is the fundamental essence of the universe, encapsulated in his phrase 'you cannot step into the same river twice.' Heraclitus's thoughts on change and unity have profoundly influenced philosophy, science, and theology throughout history.

Heraclitus of Ephesus's concept of flux and logos influenced the development of philosophical prose-poetry. His fragmented style and exploration of unity in opposites resonated with later Romantic poets, such as John Keats, who sought to capture the sublime and the transient nature of existence in their works.