Heraclitus, a Greek philosopher, is quoted as saying "change is the only constant in life." This saying has also been translated to "the only constant is change." Heraclitus is believed to have written a book where this saying was found; however, the book was destroyed and exists only in fragments.
This Heraclitus quote was found in one of the more than 100 fragments of his writings, works that are believed to have been a part of his book. He was a theorist who created doctrines about the constant change and flux of life. He lived in Ephesus, near modern Kusadasi, Turkey, around 500 B.C.