afraid of one’s own shadow

Extremely timid, excessively fearful. In Richard III (c. 1513), Sir Thomas More wrote, “Who may lette her feare her owne shadowe,” although a few years later Erasmus cited Plato as having said the same thing in Greek hundreds of years before. Henry David Thoreau used the phrase to describe the timidity of Concord’s town selectmen in refusing to toll the parish bell at John Brown’s hanging (1859), and by then it had been in use for at least two centuries.