#division. well it is like left and right hand, when you define it in your head then you become a left handed or right..else both hand are equal. Now apply that to #introvert and #extrovert.. you don't see it until you define it, it is not just seeing the effect instead you further amplified ... the amplification is the intention for those who have defined these words. hope you understand #division now, maybe not because you thinking they enable you to gain something from it - #knowledge.