ressembler à l'âne de buridan

Jean Buridan was a dialectician of the fourteenth century, and Rector of the University of Paris. One of his most famous dilemmas was that of the donkey equally hungry and thirsty, which was placed halfway between a pail of water and a load of hay. If the animal had no free-will, it would remain motionless between two equal attractions, and so die of hunger and thirst.