Etiology (alternately aetiology, aitiology) is the study of causation. It comes from the Greek meaning 'concerned with origins' so can refer to myths as well as medical and philosophical theories.
Origin and usage of term
The term (deriving from the Greek words Template:Polytonic aitia = cause and Template:Polytonic logos = word/speech) is used in philosophy, physics, psychology, and biology in reference to the causes of various phenomena. It is generally the study of why things occur, or even the reasons behind the way that things act.
In medicine in particular, the term refers to the causes of diseases or pathologies. An example of the usage can be found in Ref. , which discusses the etiology of cleft lips and explains several methods used to study causation.
- In Biblical criticism, etiologies give theological explanations for names or occurrences. Example: the story of Lot's wife in Genesis 19 (specifically 26) explains why there are pillars of salt in the area of the Dead Sea. 
- A second example might be that of the setting of the rainbow in the heavens as a sign of God's covenant with Noah - and through him all mankind (Genesis 9). In this instance the episode is included in the mythic story of the flood: a myth common in mesopotamian influenced civilizations. In this case the etiology is incidental to the myth.
- An etiological myth is a myth intended to explain a name or create a mythic history for a place or family. For example, the name Delphoi and its associated deity, Apollon Delphinios, are explained in the Homeric Hymn which tells how Apollo carried Cretans over the sea in the shape of a dolphin to make them his priests. While there is an actual etymological connection between Delphoi and delphis (delphus means "womb"), many etiological myths are based on popular etymology (the term "Amazon", for example). In Virgil's Aeneid (published circa 17 BC), many places are given mythical histories, but more importantly the then ruling Julian Family are related back to the mythical hero Aeneas through his son Ascanius, whose second name was Iulus (since I and J were interchangeable Iulus become Julus and thence the Julians).
An example of the word in use:
|“||...there is on the other a tendency to attribute all diseases of unknown aetiology to 'viruses'. In some ways, it is similar to possession by demons in medieval times, and we could make a case for the virus as a 'demon',||”|
- -- Ref.