Occam’s razor, also known as the principle of parsimony, is a problem-solving heuristic that states “entities should not be multiplied beyond necessity”. It advocates that when presented with competing hypotheses, you should select the one with fewer parameters or fewest assumptions. It is not a rule for choosing between those making different predictions, but a rule for those competing for the same prediction.
The heuristic is named after William of Ockham, an English scholastic philosopher and theologian. He began by stating “plurality must never be posited without necessity”. His deductive reasoning has been employed by many great thinkers. A later formulation by Issac Newton was reminiscent, “we are to admit no more causes of natural things than such as are both true and sufficient to explain their appearances. Therefore, to the same natural effects we must, as far as possible, assign the same causes”.
“Simplicity is the ultimate sophistication”, Leonardo da Vinci. Many people oversimplify Occam’s razor to mean the simplest answer is usually correct. This is incorrect. Rather, you shouldn’t overcomplicate, you shouldn’t “stack” a theory if a simpler explanation was at the ready. Prune the excess.
What is a heuristic?
A heuristic is a mental shortcut that enables us to make faster judgements in situations that are ill-defined, vague or complex. Although efficient, heuristics can be either helpful or damaging depending on the context.
What is a “razor”?
A philosophical razor is a type of heuristic. They aim to enable us to create and provide better explanations by discounting complex or unlikely explanations.
Why use Occam’s razor?
Selecting the hypothesis with the fewest number of necessary assumptions means it is easier to prove or disprove that hypothesis, this is due to having fewer assumptions to vet. Simple theories are easier to verify. Simple solutions are easier to execute.
In the scientific method, Occam’s razor isn’t considered an irrefutable principle of logic. The preference for simplicity is based on the falsifiability criterion. This means that for each accepted explanation of a phenomenon, there is an extensively large, sometimes incomprehensible number of possible and more complex alternatives. Failing explanations may always be encumbered with ad hoc hypotheses to present falsification. Simpler theories however, are more preferable to complex ones as they are more testable.
Occam’s razor may be used in a broad range of situations as means to making rapid decisions and establishing truths without empirical evidence. Although not comprehensive, it excels in making initial conclusions before the full scope of information can be obtained.
Exceptions and issues
As with all mental models, Occam’s razor is not foolproof. Careful consideration must be completed when confronted with important or risky decisions. There are exceptions to any rule, and one should never blindly follow results of mental models when logic, experience, or empirical evidence contradict.
A conclusion cannot only rely upon simplicity. Evidence must be applied whenever possible. When using Occam’s razor we must be vigilant, so as to not fall prey to confirmation bias. Opting for a simpler explanation still requires due diligence. It is not intended to be a substitute for critical thinking, rather a tool for efficiency.
The use of Occam’s razor
Occam’s razor may be used in a broad range of situations as means to making rapid decisions and establishing truths without empirical evidence. Although not comprehensive, it excels in making initial conclusions before the full scope of information can be obtained.
It can in principle be applied to all things, code, investing, reasoning, etc. It is a critical concept to understand when developing fundamental, differentiated insights. When developing understanding and perspective, cut down to the critical assumptions or variables.
Cut away the noise.
