Rational vs. Rationale
raâ‹…tionâ‹…al [rash-uh-nl, rash-nl] raâ‹…tionâ‹…ale [rash-uh-nal]
–adjective –noun
1. agreeable to reason; reasonable; sensible: a rational plan 1. the fundamental reason or reasons serving to account for
for economic development.
something.
2. having or exercising reason, sound judgment, or good
sense: a calm and rational negotiator. 2. a statement of reasons.
3. being in or characterized by full possession of one's reason; 3. a reasoned exposition of principles.
sane; lucid: The patient appeared perfectly rational.
• Ra`tion*a"le, n. [L. rationalis, neut. rationale. See Rational, a.]
4. endowed with the faculty of reason: rational beings.
An explanation or exposition of the principles of some opinion,
5. of, pertaining to, or constituting reasoning powers: the
rational faculty. action, hypothesis, phenomenon, or like; also, the principles
6. proceeding or derived from reason or based on reasoning: themselves.
a rational explanation.
7. Mathematics.
– capable of being expressed exactly by a ratio of two
integers.
– (of a function) capable of being expressed exactly by a
ratio of two polynomials.
8. Classical Prosody. capable of measurement in terms of the
metrical unit or mora.
• Usage: Rational, reasonable. Rational has reference to reason as
a faculty of the mind, and is opposed to traditional; as, a rational
being, a rational state of mind, rational views, etc. In these cases
the speculative reason is more particularly, referred to.
Reasonable has reference to the exercise of this faculty for
practical purposes, and means, governed or directed by reason;
as, reasonable prospect of success.
Source: http://dictionary.reference.com/