“Knowledge itself is power.”
— Francis Bacon (1597)
Most of the time we want knowledge. Knowing means understanding what is true and perhaps being able to shape events toward our own ends. Ignorant people are generally not esteemed (though sometimes we might envy the person who is in a bad situation but does not know enough to be troubled by it; that’s when we say, “Ignorance is bliss”). We seek knowledge both for the advantages it gives us and even for its own sake. In a great many cases, if not in every case, it is simply better to know than not to know. Philosophers sometimes have said that the pursuit of knowledge is essential to human nature. “All humans by nature desire to know” is how Aristotle begins his Metaphysics.
Because knowledge is so important to us, we fight over it. One group claims that X is true, another group insists that X is false, and a fight breaks out at least in words, if not in fisticuffs, over whether X is true—which is to say whether it should count as known. Authoritative institutions often seek to control knowledge both in terms of who can have it and what should count as known. We often turn to science as an institution to decide whether claims are known or not, which gives “science” – meaning scientists, at universities and in research labs – a huge amount of power. Each year the world spends a trillion dollars on research and development in science which means there is a lot of money we are willing to spend on figuring out what is known.
So, what is knowledge? What is it to know something? Philosophers usually start to answer big questions like this by making distinctions and making the discussion more precise.