“The explanation requiring the fewest assumptions is most likely to be correct.”
“When you have two competing theories that make exactly the same predictions, the simpler one is the better.”
“With all things being equal, the simplest explanation tends to be the right one.”
“Entities should not be multiplied beyond necessity.”
“Entia non sunt multiplicanda praeter necessitatem.”
“Keep things simple.”
“Pluralitas non est ponenda sine neccesitate. (Entities should not be multiplied unnecessarily.)”