What does irrationalised mean?
Irrationalised is the past tense and past participle of the British verb irrationalise, meaning to make something irrational or render it contrary to reason. It is often used of beliefs, decisions, behaviour, institutions, and numerical systems whose supposedly objective character has been undermined by emotion, prejudice, distortion, or faulty logic. The word may also imply that a person or organization has adopted a deliberately unreasonable position, although it does not necessarily mean that the irrationality was intentional. In American English, irrationalized is more common. As a participial adjective, irrationalised can describe the resulting condition: an irrationalised argument differs from one that was irrational from the outset because something has actively made it so. The verb is relatively formal and evaluative, and it is especially effective when discussing the process by which apparently reasonable systems acquire unreasonable features. Its related noun, irrationalisation, names that process.
To make or render something or someone irrational.
"Ideological bias irrationalised the committee's assessment."
Common in formal and analytical contexts; chiefly British in its -ise spelling.
Having been made irrational or rendered unreasonable.
"The irrationalised estimates produced a misleading sense of confidence."
This is a participial use of the verb rather than a regularly inflected adjective.
A number can be wrong; irrationalised, it becomes a convincing way of avoiding reason altogether.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does irrationalised come from?
The English adjective irrational comes from Latin irrationalis, a negative form of rationalis, meaning not rational or not reasonable. The verb irrationalise was formed in British English by adding the suffix -ise to irrational, following the model of rationalise. Its American form uses the alternative suffix -ize, reflected in irrationalized and irrationalization.
Related word forms
How irrationalised is actually used
The form with -s is standard in British English, while the corresponding US spelling is usually irrationalized. The term is generally critical or analytical rather than neutral, suggesting that a process, belief, or decision has been stripped of rational basis.
Easily confused with irrationalised
Rationalised means made logical, reasonable, or mathematically exact, whereas irrationalised means made irrational or unreasonable.