Dogs bark at whoever they don't know.

The source

"Dogs bark at whoever they don't know." Heraclitus said it in Fragment B97 (Diels-Kranz). Translated from the original Greek by Spartan Surfers.

"κύνες γὰρ καταβαΰζουσιν ὧν ἂν μὴ γινώσκωσι."

Original Greek, Fragment B97 (Diels-Kranz). Greek: Diels-Kranz fragment text via el.wikisource.

Who said it

Heraclitus (c. 535–475 BC). Philosopher of Ephesus who taught that everything flows. Only fragments of his book survive.

Questions

Who said "Dogs bark at whoever they don't know."?

Heraclitus (c. 535–475 BC). Source: Fragment B97 (Diels-Kranz).

What is the original Greek?

κύνες γὰρ καταβαΰζουσιν ὧν ἂν μὴ γινώσκωσι. Translated from the original Greek by Spartan Surfers.