•  Balance of trade figures, also called net exports (NX), are the sum of the money gained by a given economy by selling exports, minus the cost of buying imports. They form part of the balance of payments, which also includes other transactions such as the international investment position.

•  The Great Depression was a massive global economic recession (or "depression") that ran from 1929 to approximately 1939. The term Great Depression can refer to the economic event, but it can also refer to the cultural period, often called simply "The Depression", and to the political response to the economic events.

•  The Organization of the Petroleum Exporting Countries (OPEC) is made up of Algeria, Indonesia, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, the United Arab Emirates and Venezuela; since 1965, its international headquarters have been in Vienna, Austria. The principal aim of the Organization, according to its Statute, is the coordination and unification of the petroleum policies of its member countries and the determination of the best means for safeguarding their interests.

•  In quantum physics, the Heisenberg uncertainty principle states that one cannot assign with full precision values for certain pairs of observable variables, including the position and momentum, of a single particle at the same time. It furthermore precisely quantifies the imprecision by providing a lower bound (greater than zero) for the product of the standard deviations of the measurements. The uncertainty principle is one of the cornerstones of quantum mechanics and was discovered by Werner Heisenberg in 1927.It is sometimes called the Heisenberg indeterminacy principle (a name prefered by Niels Bohr). In common usage the idea that when you observe any action you affect it has taken hold. An example would be that when a TV crew films an event, the people filmed act differently knowing that they are being broadcast on TV. It is often linked with such things as TV reality shows.

•  The Spanish Inquisition was the Inquisition acting in Spain under the control of the Kings of Spain. This Inquisition was the result of the reconquest of Spain from the Muslims and the policy of punishing with brutal torture those accused of heresy and witchcraft, and of converting Spanish Jews and Muslims to Christianity. "Spanish Inquisition" has come to mean any harsh questioning or cruel treatment.

•  Zeitgeist is originally a German expression that means "the spirit (Geist) of the time (Zeit) ". It denotes the intellectual and cultural climate of an era. (collective consciousness, collective unconscious in psychology)

  Quotations about Zeitgiest

“Whoever marries the zeitgeist will be a widower soon.” - August Everding

“Opinions, that deviate from the ruling zeitgeist, always aggravate the crowd.” - Germaine de Stael

“The product of paper and printed ink, that we commonly call the book, is one of the great visible mediators between spirit and time, and, reflecting zeitgeist, lasts as long as ore and stone.” - Johann Georg Hamann

•  Niccolò Machiavelli (May 3, 1469 – June 21, 1527) was a Florentine statesman, political philosopher, historian, musician, poet, and comedic playwright. As a theorist, Machiavelli was the key figure in realist political theory, crucial to European statecraft during the Renaissance. His two most famous books, Discorsi sopra la prima deca di Tito Livio ( Discourses on Livy ) and Il Principe ( The Prince ), were written in the hopes of improving the conditions of the Northern Italian principalities, but became general handbooks for a new style in politics. The Prince, written to encourage the appearance of a political savior who would unify the corrupt city-states and fend off foreign conquest, advocated the theory that whatever was expedient was necessary—an early example of realpolitik .

•  The Dead Sea Scrolls comprise roughly 850 documents, including texts from the Hebrew Bible, discovered between 1947 and 1956 in eleven caves in and around the Wadi Qumran (near the ruins of the ancient settlement of Khirbet Qumran, on the northwest shore of the Dead Sea). The texts are of great significance in a religious context (as well as a political context), as they are practically the only remaining Biblical documents dating from before AD 100.

•  Status quo is a Latin term meaning the present current, existing state of affairs. To maintain the status quo is to keep things the way they presently are. Compare it with status quo ante , meaning "the state of things as it was before." Arguing to preserve the status quo is usually done in the context of opposing a large, often radical change. The term frequently refers to the status of a large issue, such as the current culture or social climate of an entire society or nation. Politicians sometimes refer to a status quo . Sometimes there is a policy of deliberate ambiguity, referring to the status quo rather than formalizing the status. An example of political ambiguity is the political status of Taiwan.

•  Mea Culpa is a Latin phrase that translates into English as "my fault", or "my own fault". In order to emphasize the message, the adjective "maxima" may be inserted, resulting in " mea maxima culpa ", which would translate as "my [most] grievous fault". The origin of the expression is in a part of the Catholic mass known as Confiteor (Latin for "I confess"), in which the individual recognizes his or her flaws before God. Despite its appearance, the "mea culpa", as the Confiteor has come to be known popularly, is not a confession of sins, but rather an admission of one's flawed nature and the willingness to make amends for it.