Galileo's law of inertia was basis of Newton's laws of motion.

Newton's first law of motion : Every body continues to be its state of rest or uniform motion in a straight line unless compelled by some external force to act otherwise.

A body at rest or motion of body moving with constant velocity both represent zero acceleration. Hence, Newton's first law can be represented as follows :

Force is a physical quantity which can bring body at rest into motion and which can change velocity of object.

In short, physical quantity which can produce acceleration in body is called force.

From Newton's first law magnitude of force can not be known. This is its limitation.