to its natural motion. So he concluded that continuation of motion is attributed to the inclination that is transferred to the object, and that object will be in motion until the mayl is spent. He also claimed that a projectile in a vacuum would not stop unless it is acted upon, consistent with Newton's first law of motion.

On the question of a body subject to a constant (uniform) force, the 12th-century Jewish scholar Hibat Allah Abu'l-Barakat al-Baghdaadi says that acceleration