Aristotle famously defined the human being as (Formula presented) (a living thing with logos). Heidegger and Arendt both questioned the interpretation of animal rationale (rational animal). Tracing back to ancient Greek thoughts, they both regarded the original meaning of λόγος as speech and illustrated the relationship between speech and human existence. Heidegger elucidated the disclosing nature of speech and distinguished between authentic and inauthentic forms of speech. Heidegger emphatically examined inauthentic everyday speech, while Arendt was more concerned with exploring an authentic form of public discourse. This paper explains the connection and distinction between Heidegger’s and Arendt’s views on speech. It argues that Arendt develops Heidegger’s notion of speech by expositing an authentic and active public speech.