/in dif"euhr euhns, -dif"reuhns/, n.1. lack of interest or concern: We were shocked by their indifference toward poverty.2. unimportance; little or no concern: Whether or not to attend the party is a matter of indifference to him.3. the quality or condition of being indifferent.4. mediocre quality; mediocrity.[1400-50; late ME, var. of INDIFFERENCY < L indifferentia. See INDIFFERENT, -ENCE, -ENCY]Syn. 1. INDIFFERENCE, UNCONCERN, LISTLESSNESS, APATHY, INSENSIBILITY all imply lack of feeling. INDIFFERENCE denotes an absence of feeling or interest; UNCONCERN, an absence of concern or solicitude, a calm or cool indifference in the face of what might be expected to cause uneasiness or apprehension; LISTLESSNESS, an absence of inclination or interest, a languid indifference to what is going on about one; APATHY, a profound intellectual and emotional indifference suggestive of faculties either naturally sluggish or dulled by emotional disturbance, mental illness, or prolonged sickness; INSENSIBILITY, an absence of capacity for feeling or of susceptibility to emotional influences.Ant. 1. eagerness, responsiveness.
* * *in the mathematical theory of probability (probability theory), a classical principle stated by the Swiss mathematician Jakob Bernoulli (Bernoulli, Jakob) and formulated (and named) by the English economist John Maynard Keynes (Keynes, John Maynard) in A Treatise on Probability (1921): two cases are equally likely if no reason is known why either case should be the preferable one. The assumption of indifference was frequently used by the French mathematician Pierre-Simon Laplace (Laplace, Pierre-Simon, marquis de) beginning in the 1780s to calculate “inverse” or, as we now say, Bayesian probabilities (Bayes's theorem). Such assumptions became controversial in the 19th century. Keynes and his followers worked to define the conditions under which they are justified.
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