What if the opposite of the laws of motion were true?

What would happen if Newton's three laws of motion weren't true?

Examples?What if the opposite of the laws of motion were true?Thats a really good and interesting question, although don't take me word for word for this, I am merely just adding ideas.

For the Third law, for every action there is an equal and opposite reaction, everything would be falling, and if you were to put your hand on to a wall, your hand would go through the wall due to no opposing force. Imagine walking, you exert a force on the ground and the ground exerts a force back on you. Walking could not be achieved nor could sitting.