We can only know our Self in relationship to the Other or our environment (dividualism), the same way we can only know joy if we know suffering; lightness if we've experienced darkness. Energetically, it is impossible to separate duality (opposing forces) from our Self. This holds true for our physical structure as well. The body is unable to stand up, sit down, bend over, twist sideways without muscular tension. Muscles work together one actively working while one stabilizes. If all muscles were relaxed we would fall apart into a pile of bones. Thus a balance of effort and ease is not only necessary, it is unavoidable and our truest state of being.