Retrospective determinism


Retrospective determinism is the informal fallacy that because something happened under some circumstances, it was therefore bound to happen due to those circumstances; the term was coined by the French philosopher Henri Bergson. For example:
Were this an argument, it would give no rational grounds on which to conclude that Caesar's assassination was the only possible outcome, or even the most likely outcome under the circumstances. This type of fallacy can precede a hasty generalization: because something happened in given circumstances, it was not only bound to happen, but will in fact always happen given those circumstances. For example:
Not only is this irrational, it is factually false.