Coincidence

A coincidence is a remarkable concurrence of events or circumstances that have no apparent causal connection with one another. The perception of remarkable coincidences may lead to supernatural, occult, or paranormal claims, or it may lead to belief in fatalism, which is a doctrine that events will happen in the exact manner of a predetermined plan. In general, the perception of coincidence, for lack of more sophisticated explanations, can serve as a link to folk psychology and philosophy. From a statistical perspective, coincidences are inevitable and often less remarkable than they may appear intuitively. Usually, coincidences are chance events with underestimated probability. An example is the birthday problem, which shows that the probability of two persons having the same birthday already exceeds 50% in a group of only 23 persons. The first known usage of the word is from c. 1605 with the meaning "exact correspondence in substance or nature" from the French coincidence, from coincider, from Medieval Latin coincidere. The definition evolved in the 1640s as "occurrence or existence during the same time". The word was introduced to English readers in the 1650s by Sir Thomas Browne, in A Letter to a Friend (circa 1656 pub. 1690) and in his discourse The Garden of Cyrus (1658). Synchronicity Swiss psychiatrist Carl Jung developed a theory that states that remarkable coincidences occur because of what he called "synchronicity," which he defined as an "acausal connecting principle." One of Kammerer's passions was collecting coincidences. He published a book titled Das Gesetz der Serie (The Law of Series), which has not been translated into English. In this book, he recounted 100 or so anecdotes of coincidences that led him to formulate his theory of seriality. He postulated that all events are connected by waves of seriality. Kammerer was known to make notes in public parks of how many people were passing by, how many of them carried umbrellas, etc. Albert Einstein called the idea of seriality "interesting and by no means absurd.