Laws vs Theories & Principles

There is a common misunderstanding that a scientific “Theory” is somehow speculative, but that a scientific “Law” has been proven and can be relied upon.  This is not the case.  Sometimes a “Theory” (eg. Einstein’s Relativity) is much more accurate and better supported by evidence than a related “Law”  (eg. Newton’s Motion and Gravity).   


There is no clear consistently applied rule concerning what is a “law” and what is a “theory/principle/formula”.  Before the last half of the 19th century, useful equations were routinely proclaimed to be “Laws” (eg. Hooke’s, Boyle’s, Thermodynamics, Conservation of Energy).  After that a major shift away from labelling an idea a law took place, at a time when there was a growing realization that even well-established equations such as Newton’s were at best only approximations (though often very good approximations) of how the world behaves.  This understanding is at the core of the scientific way of thinking:

  • that nothing is to be taken as being true solely on authority,
  • that evidence is to be scrutinized methodically and without preconception,
  • that even our most cherished beliefs may be proven wrong and have to be revised.

At its core, science accepts and embraces uncertainty.


But acknowledging that our understanding of the world around us, and within us, is incomplete does not mean that all ideas are of equal merit and should be given equal status.

Many well-known ideas, even those that align with our intuition and have been firmly held by millions of people over centuries, are little more than speculations unsupported by solid evidence.  Some are even held despite overwhelming evidence to the contrary.  Others, including some (such as Quantum Mechanics) that completely clash with our intuition, allow us to manipulate the world around us with great power and precision.  If we are to continue to use this power and have it be beneficial rather than harmful, we must do our best to accurately understand how are actions will affect the world.  This means being humble in the face of the limitations of our understanding of the world, questioning our beliefs, and rigorously looking for evidence that would undermine these beliefs.

This level of uncertainty is often discomforting and takes effort to maintain. 


Interestingly, even as those who study the natural world have moved away from declaring ideas to be “Laws”, some who study human behaviour, especially economists, continue to use the term to describe insights that lack solid support of evidence and cannot be reliably applied across cultures and societies.  Simply calling something a “law” doesn’t make it true or meaningful.