sin vs. symtom

The play that I watched for my artist review has really brought some great questions to mind for me. I have really wanted to discus "sin vs. symptom." To me the phrase asks the question of whether people always have complete control of their actions or not. Do we ever stop to think why people make "bad choices" rather than just pointing and shacking the finger? There is no shame in coughing when one has a cold. We far too often try to separate the mental from the physical. The brain is in fact a part of the working body so when then can't it have its own symptoms like the pancreas with diabetes. We as humans have an innate desire to control and the thought of not being in complete control of decisions is a thought to terrifying to imagine. In an attempt to organize we also put a weight on "sin." Some call them mortal sins. Is there really a difference in a serial killing and running a red light. The weight depends how much the choice affects the surrounding people. In reality though, if they are both symptoms what is the difference?