Occlusion is a much dreaded fact that may occur in some intestinal surgery, due to youth, haste, or just sheer incompetence from one fated to be a false surgeon. It may also be a pathological outcome of some serious unnatural illness which paradoxically forms part of human nature. It consists of a blockage of the intenstinal lumen which prevents the discharge of waste to the external milieu. In its mildest forms, it provokes farts. Non-positivist, real scientific conclusions are the door of entry to new discoveries or doubts, and must not be occlusive: as Winnicott said (in Home is Where We Start From, 1986), the worst thing that could happen to a scientist would be that he felt he had reached a dead end—as may exist on railway routes.