Rational - rationale

It is easy to confuse the spelling of the adjective rational with the spelling of the noun rationale. Don't do it!

• The basic meaning of the adjective rational, pronounced with the stress on the first syllable 'RASH-'n-'l' (IPA: /ˈræʃ ən əl/), is 'to do with [the mental power of] reason', 'to do with logical thought'. So a person can be rational, by using considered qualities of thought in decisions. (Human beings are rational creatures, and it was traditionally held, with very little basis, that men are more rational beings than women.) A

Until the second half of the twentieth century, the final '-e-' of rationale was sounded, 'rash-on-ALE-y'. IPA: //