Belief vs Knowledge

What's the difference?

Knowing vs. Believing

The key difference between knowledge and belief is in how each is justified.

  • Knowledge: a reasonable claim to knowledge must be:
    • logical: limited to evidence–based reasoning that is both true and valid
    • falsifiable: a way exists to prove whether or not it’s correct
    • precise: not made of arbitrary parts
  • Belief: a belief need only be
    • consistent with the psychological state of the claimant

1. Does it have to be logical?

  • Knowledge: Must it be logical? Yes.
    • All knowledge must be logical—by making claims that are true, valid and sound.
    • In other words, knowledge is limited to the rigorous process of evidence and reason. Belief is not.
  • Belief: Must it be logical? No. Beliefs can be, but there's no rule that says beliefs must be logical.

Examples of logical statements of knowledge:

  • I know Force equals Mass times Acceleration.
  • I know the film Argo won the 2013 Academy Award for Best Picture.

Example of a logical statement of belief:

  • I believe my office building will survive a tornado.

Example of an illogical statement of belief:

  • I believe the President must be a great banjo player, because only great musicians make great presidents.

2. Can it be proven false?

  • Knowledge: Can it be proven false? Yes.
    • The cultural claim, "Ottawa is the capital of Canada" is the kind of claim that can be proven or disproven by checking an official map of Canada. Scientific claims and mathematical claims also fall into this kind of falsifability.
    • Logically, if a claim cannot be proven false, then it cannot be meaningfully true either.
    • This is the test:
      • Bob claims to know X about the world.
      • Is there a way to prove or disprove that X is true?
      • If not, then Bob cannot meaningfully state that he "knows X"—it is only his personal belief, opinion, or feeling.
  • Belief: Claims based on psychological states (such as beliefs) cannot be disproven.
    • A person expressing a claim about how they feel cannot be internally wrong. Even if his statement doesn't line up with previous statements, it's possible that the person has since changed his mind.

Examples of falsifiable truth–claims (knowledge):

  • Ottawa is the capital of Canada
  • 2+2=4

Examples of unfalsifiable truth–claims (beliefs):

  • The Mona Lisa is the most beautiful painting ever
  • Football is the best sport in the world

3. How precise does it have to be?

  • Knowledge: Must it be precise? Yes.
    • For truth–claims to be considered knowledge, they must be precise in a meaningful way so as to enable their falsifiability.
  • Belief: Must it be precise? No.
    • Beliefs can be vague statements or predictions about the world.

Example of a precise statement about the world (knowledge):

  • A calorie is the amount of energy needed to raise 1 gram of water by 1 degree celcius.

Example of an arbitrary statement about the world (belief):

  • A person's well–being depends on their overall sense of unity and balance.

Final Thought: What about people who ignore the distinction?

What about those who say "I don't just believe it… I know it!" As if knowing is just a stronger word for believing...

  • If the distinction between knowledge and belief is ignored, then said person is most likely either:
    • 1. Unaware of the distinction, or
    • 2. Doesn't care about the distinction
  • If the person is ignorant of the distinction (1), then they would be well–served by acquainting themselves of the distinction. 
  • If someone does not value the distinction between knowledge and belief (2), then there is nothing more to be done. It is pointless to argue with someone who doesn't value evidence and reason, since logical argumentation depends upon both.
  • But consider this… Read the following two claims and decide if there is or isn't a distinction between them.
    • Imagine that you are suffering from a painful disease. All evidence points to the fact that the disease is curable, so you go to a certified specialist in the medical field who claims to have knowledge of your condition. She answers all your questions with charts, graphs, and statistics of success rates. She then prescribes a precise regiment of pills and continued care. 
    • Now imagine that your neighbor sees you at the pharmacy and tries to disuade you from taking the prescribed pills. When you ask him why, he tells you that he thinks the pills will make you worse but offers no scientific explanation as to why.
    • Are these two people making the same kind of claim? Or can we meaningfully call one knowledge–based and one a belief?
  • Lastly, let us be clear: beliefs can be useful and valuable. The point of this article isn't to deny the use or value of beliefs; it is simply to underline the difference between a knowledge–claim and a personal or shared belief.