The famous definition of history as "the unending dialogue between the present and the past" comes from E.H. Carr, the British historian and political scientist. He articulated this idea in his influential 1961 book What is History?, which remains one of the most widely read works on historical methodology.
Carr argued that history is not simply a fixed collection of facts waiting to be discovered, but rather an ongoing process of interaction between the historian and the evidence. The historian selects, interprets, and gives meaning to facts from the past, and this interpretation is inevitably shaped by the historian's own time, circumstances, and perspectives. In this sense, the study of history is a continuous "dialogue" - the past provides the raw material, and the present provides the questions, frameworks, and concerns that shape how that material is understood.
The other figures listed are significant historians but are associated with different contributions. Herodotus (5th century BC) is known as the "Father of History" for writing the first systematic historical narrative. Thucydides, his contemporary, wrote a rigorous account of the Peloponnesian War emphasising evidence and analysis. Arnold Toynbee was a 20th-century British historian known for his multi-volume A Study of History, which examined the rise and fall of civilisations. None of them coined the phrase in question.