"One of the first things a relationship therapist learns is that couples argue to burn up energy that could be used for something else. In fact, arguments often serve the purpose of using up energy, so that the couple do not have to take the courageous, creative leap into an unknown they fear. Arguing serves the function of being a zone of familiarity into which you can retreat when you are afraid of making a creative breakthrough."
Thanks to C.R.L. who sent me to the site where I saw this quote.