This article described three heuristics that are employed in making judgements under uncertainty: representativeness, which is usually employed when people are asked to judge the probability that an object or event A belongs to class or process B; availability of instances or scenarios, which is often employed when people are asked to assess the frequency of a class or the plausibility of a particular development; and adjustment from an anchor, which is usually employed in numerical prediction when a relevant value (...) is available. These heuristics are highly economical and usually effective, but they lead to systematic and predictable errors. A better understanding of these heuristics and of the biases to which they lead could improve judgements and decisions in situations of uncertainty. (shrink)

Feyerabrend argues that intellectual progress relies on the creativity of the scientist, against the authority of science.

Mill predicted that "[t]he Liberty is likely to survive longer than anything else that I have written...because the conjunction of [Harriet Taylor’s] mind with mine has rendered it a kind of philosophic text-book of a single truth, which the changes progressively taking place in modern society tend to bring out in ever greater relief." Indeed, On Liberty is one of the most influential books ever written, and remains a foundational document for the understanding of vital political, philosophical and social issues. (...) In addition to its many useful appendices, this new edition includes a chronology, bibliography, and a substantial introduction which outlines Mill’s life and works, and sets this central work of 1859 in the context of both his own intellectual development and of the play of ideas and political forces in Victorian society. (shrink)

Although, when first introduced, Copernicus's theory considered as a whole was not superior to the Ptolemaic theory according to any of the usual criteria for comparing theories and determining their acceptability, it did have features which provided the early Copernicans with good reasons for entertaining it and trying to develop it further. These features are discussed and then three plausibility considerations which seem to be operative in this case are formulated.

This was scanned from the 1909 edition and mechanically checked against a commercial copy of the text from CDROM. Differences were corrected against the paper edition. The text itself is thus a highly accurate rendition. The footnotes were entered manually.