This is what I want to use, and this is how I just saw it written:
For every action there is an equal and opposite reaction.

That is not the actual quote though,is it?

That's Newton's Third Law of Motion.
It states that when one body exerts a force on another body (an action force), the second body exerts an equal force in the opposite direction on the first (the reaction force).
F(A on B)= -F(B on A)

But people usually just say "For every action there is an equal and opposite reaction", especially if they're not in a physics class at the time.

Thank you Rala.