The simplest explanation is usually the right one. Also known as the Occam's razor or the law of parsimony. The Occam's razor is used a heuristic in Science to develop theoretical models. In the scientific method, you could reach different conclusions based on the evidence from the experiment. But using Occam's razor in this case wouldn't be that useful. It is not axiomatic that the simpler one should be the right one. So taking that into consideration, the Occam's razor could also be stated as "If all else remains equal, a simpler explanation is preferred over a complex one". What is a simpler explanation to one may not be the most simpler one for someone else. Maybe the Occam's razor is another way of saying what is the most simpler one is the most rational one. The option that agrees with all the knowledge and logic that you already have.