Retrospective determinism is the

informal fallacy Informal fallacies are a type of incorrect argument in natural language. The source of the error is not just due to the ''form'' of the argument, as is the case for formal fallacies, but can also be due to their ''content'' and ''context''. Fall ...

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: :''When he declared himself

dictator A dictator is a political leader who possesses absolute power. A dictatorship is a state ruled by one dictator or by a small clique. The word originated as the title of a Roman dictator elected by the Roman Senate to rule the republic in tim ...

of the

Roman Republic The Roman Republic ( la, Res publica Romana ) was a form of government of Rome and the era of the classical Roman civilization when it was run through public representation of the Roman people. Beginning with the overthrow of the Roman Ki ...

Julius Caesar Gaius Julius Caesar (; ; 12 July 100 BC – 15 March 44 BC), was a Roman general and statesman. A member of the First Triumvirate, Caesar led the Roman armies in the Gallic Wars before defeating his political rival Pompey in a civil war, ...

was bound to be assassinated.'' 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 A faulty generalization is an informal fallacy wherein a conclusion is drawn about all or many instances of a phenomenon on the basis of one or a few instances of that phenomenon. It is similar to a proof by example in mathematics. It is an examp ...

: because something happened in given circumstances, it was not only bound to happen, but will in fact always happen given those circumstances. For example: :''Caesar was assassinated when he declared himself dictator.

Sic semper tyrannis ''Sic semper tyrannis'' is a Latin phrase meaning "thus always to tyrants". In contemporary parlance, it means tyrannical leaders will inevitably be overthrown. The phrase also suggests that bad but justified outcomes should, or eventually will ...

: this goes to show that all dictators will eventually be assassinated.'' Not only is this irrational, it is factually false.

See also