Wisdom is the judicious application of knowledge. It is a deep understanding and realization of people, things, events or situations, resulting in the ability to apply perceptions, judgments and actions in keeping with this understanding. It often requires control of one's emotional reactions (the "passions") so that universal principles, reason and knowledge prevail to determine one's actions. Wisdom is also the comprehension of what is true coupled with optimum judgment as to action. Synonyms include: sagacity, discernment, or insight.

Philosophical perspectives of wisdom
A basic definition of wisdom is the use of knowledge. The opposite of wisdom is folly.
 
The ancient Greeks considered wisdom to be an important virtue, personified as the goddesses Metis and Athena. Athena is said to have sprung from the head of Zeus. She was portrayed as strong, fair, merciful, and chaste. To Socrates and Plato, philosophy was literally the love of Wisdom (philo-sophia). This permeates Plato's dialogues, especially The Republic, in which the leaders of his proposed utopia are to be philosopher kings: rulers who understand the Form of the Good and possess the courage to act accordingly. Aristotle, in his Metaphysics, defined wisdom as the understanding of causes, i.e. knowing why things are a certain way, which is deeper than merely knowing that things are a certain way.
 
The ancient Romans also valued wisdom. It was personified in Minerva, or Pallas. She also represents skillful knowledge and the virtues, especially chastity. Her symbol was the owl which is still a popular representation of wisdom, because it can see in darkness. She was said to be born from Jupiter's brain.
 
Wisdom is also important within Christianity. Jesus emphasized it. Paul the Apostle, in his first epistle to the Corinthians, argued that there is both secular and divine wisdom, urging Christians to pursue the latter. Prudence, which is intimately related to wisdom, became one of the four cardinal virtues of Catholicism. The Christian philosopher Thomas Aquinas considered wisdom to be the "father" (i.e. the cause, measure, and form) of all virtues.
 
In the Inuit tradition, developing wisdom was the aim of teaching. An Inuit Elder said that a person became wise when they could see what needed to be done and do it successfully without being told what to do.
 
The Native American's philosophy about being a part of the natural environment contrasted to the European's culture of conquering nature's gifts. The Native American's wisdom about maintaining balance ecologically and socially was a common-sense approach to protecting and conserving natural resources.
 
Educational perspectives of wisdom
Public schools in the US have an approach to character education. In Benjamin Franklin’s time, it was referred to as training wisdom and virtue. Traditionally, schools share the responsibility to build character and wisdom along with parents and the community.
 
Nicholas Maxwell, a contemporary philosopher in the United Kingdom, advocates that academia ought to alter its focus from the acquisition of knowledge to seeking and promoting wisdom, which he defines as the capacity to realize what is of value in life, for oneself and others. He teaches that new knowledge and technological know-how increase our power to act which, without wisdom, may cause human suffering and death as well as human benefit.
 
Psychological perspectives
Psychologists have gathered data on commonly held beliefs or folk theories about wisdom. These analyses indicate that although "there is an overlap of the implicit theory of wisdom with intelligence, perceptiveness, spirituality and shrewdness, it is evident that wisdom is a distinct term and not a composite of other terms." Many, but not all, studies find that adults' self-ratings of perspective/wisdom do not depend on age. This stands in contrast to the popular notion that wisdom increases with age, supported by a recent study showing that regardless of their education, IQ or gender, older adults possess superior reasoning about societal and interpersonal conflicts. In many cultures the name for third molars, which are the last teeth to grow, is etymologically linked with wisdom, e.g. as in the English wisdom tooth. In 2009, a study reviewed which brain processes might be related to wisdom.
 
Researchers in the field of positive psychology have defined wisdom as the coordination of "knowledge and experience" and "its deliberate use to improve well being." With this definition, wisdom can supposedly be measured using the following criteria.
 A wise person has self-knowledge.
 A wise person seems sincere and direct with others.
 Others ask wise people for advice.
 A wise person's actions are consistent with his/her ethical beliefs.
 
Measurement instruments that use these criteria have acceptable to good internal consistency and low to moderate test-retest reliability (r in the range of 0.35 to 0.67).

Sapience is often defined as wisdom, or the ability of an organism or entity to act with appropriate judgment, a mental faculty which is a component of intelligence or alternatively may be considered an additional faculty, apart from intelligence, with its own properties. Robert Sternberg has segregated the capacity for judgment from the general qualifiers for intelligence, which is closer to cognizant aptitude than to wisdom. Displaying sound judgment in a complex, dynamic environment is a hallmark of wisdom.
 
The word sapience is derived from the Latin sapientia, meaning "wisdom". Related to this word is the Latin verb sapere, meaning "to taste, to be wise, to know"; the present participle of sapere forms part of Homo sapiens, the Latin binomial nomenclature created by Carolus Linnaeus to describe the human species. Linnaeus had originally given humans the species name of diurnus, meaning man of the day. But he later decided that the dominating feature of humans was wisdom, hence application of the name sapiens. His chosen biological name was intended to emphasize man's uniqueness and separation from the rest of the animal kingdom.
 
In fantasy fiction and science fiction, sapience describes an essential human property that bestows "personhood" onto a non-human. It indicates that a computer, alien, mythical creature or other object will be treated as a completely human character, with similar rights, capabilities and desires as any human character. The words "sentience", "self-awareness" and "consciousness" are used in similar ways in science fiction.