this concept of multiple causation is also known as multifactorial (more than one cause) etiology.
accident are often attribute to a single act or condition, such as speeding, intoxication, or wet, slippery pavement. although all of these can be contributory factor in highway accident, it cannot be accurately stated that they are "the" cause. many people speed, drive while under influence of alcohol, and negotiate wet slippery pavement without experiencing an accident. accident result from a dynamic interaction between human and environment factors. the end result is the product of the total combination of force through which it was created. human factor are sometimes call intrinsic, and environment factors are sometime referred to as extrinsic.