Not based on clear reason or logical thinking; unreasonable or impossible to explain logically.
From Latin *irrationalis* “not reasonable,” from *in-* “not” and *rationalis* “reasonable,” from *ratio* “reason.” In math, it also describes numbers that cannot be written as simple fractions.
Humans are often proudly irrational—afraid of flying but not of driving, or buying things they don’t need. In math, irrational numbers like π never repeat or end, reminding us that not everything fits neatly into simple patterns.
The term “irrational” has often been weaponized against women, especially to stereotype them as overly emotional or incapable of reason, for example in medicalized notions like “hysteria.” Such usage contributed to excluding women from decision-making and justifying unequal legal and social treatment.
Avoid using “irrational” as a gendered stereotype or in ways that dismiss emotions, particularly when describing women or gender minorities. Focus on specific behaviors, evidence, or reasoning patterns rather than labeling a person or group as irrational.
["unsupported by evidence","inconsistent with the data","not logically justified"]
When discussing the history of rationality and science, include women philosophers, scientists, and mathematicians whose work demonstrated rigorous reasoning but was historically marginalized or attributed to male colleagues.
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