stylistic:tone, structural:reformatting
Value

Knowledge may be valuable either because it is useful or because it is good in itself. Knowledge can be useful by helping a person achieve their goals. For example, if one knows the answers to questions in an exam one is able to pass that exam or by knowing which horse is the fastest, one can earn money from bets. In these cases, knowledge has instrumental value. Not all forms of knowledge are useful and many beliefs about trivial matters have no instrumental value. This concerns, for example, knowing how many grains of sand are on a specific beach or memorizing phone numbers one never intends to call. In a few cases, knowledge may even have a negative value. For example, if a person's life depends on gathering the courage to jump over a ravine, then having a true belief about the involved dangers may hinder them from doing so.

Besides having instrumental value, knowledge may also have intrinsic value. This means that some forms of knowledge are good in themselves even if they do not provide any practical benefits. According to philosopher Duncan Pritchard, this applies to forms of knowledge linked to wisdom. It is controversial whether all knowledge has intrinsic value, including knowledge about trivial facts like knowing whether the biggest apple tree had an even number of leaves yesterday morning. One view in favor of the intrinsic value of knowledge states that having no belief about a matter is a neutral state and knowledge is always better than this neutral state, even if the value difference is only minimal.

A more specific issue in epistemology concerns the question of whether or why knowledge is more valuable than mere true belief. There is wide agreement that knowledge is usually good in some sense but the thesis that knowledge is better than true belief is controversial. An early discussion of this problem is found in Plato's Meno in relation to the claim that both knowledge and true belief can successfully guide action and, therefore, have apparently the same value. For example, it seems that mere true belief is as effective as knowledge when trying to find the way to Larissa. According to Plato, knowledge is better because it is more stable. Another suggestion is that knowledge gets its additional value from justification. One difficulty for this view is that while justification makes it more probable that a belief is true, it is not clear what additional value it provides in comparison to an unjustified belief that is already true.

The problem of the value of knowledge is often discussed in relation to reliabilism and virtue epistemology. Reliabilism can be defined as the thesis that knowledge is reliably formed true belief. This view has difficulties in explaining why knowledge is valuable or how a reliable belief-forming process adds additional value. According to an analogy by philosopher Linda Zagzebski, a cup of coffee made by a reliable coffee machine has the same value as an equally good cup of coffee made by an unreliable coffee machine. This difficulty in solving the value problem is sometimes used as an argument against reliabilism. Virtue epistemology, by contrast, offers a unique solution to the value problem. Virtue epistemologists see knowledge as the manifestation of cognitive virtues. They hold that knowledge has additional value due to its association with virtue. This is based on the idea that cognitive success in the form of the manifestation of virtues is inherently valuable independent of whether the resulting states are instrumentally useful.

Acquiring and transmitting knowledge often comes with certain costs, such as the material resources required to obtain new information and the time and energy needed to understand it. For this reason, an awareness of the value of knowledge is crucial to many fields that have to make decisions about whether to seek knowledge about a specific matter. On a political level, this concerns the problem of identifying the most promising research programs to allocate funds. Similar concerns affect businesses, where stakeholders have to decide whether the cost of acquiring knowledge is justified by the economic benefits that this knowledge may provide, and the military, which relies on intelligence to identify and prevent threats. In the field of education, the value of knowledge can be used to choose which knowledge should be passed on to the students.