Some systems of scientific thinking are too inflexible to allow for new thinking – which may even be branded as a kind of heresy if current scientific thinking also forms part of political or religious ideology. Otherwise, new theories may simply be written off as eccentricities or not worth considering. Scientific rivalry may play a part in holding back new ideas, as may the determination to cling to old and comfortable understandings.
An extreme example of scientific censorship is the emprisonment of the Italian mathematician Galileo by the Vatican counsel in 1633. Galileo's conjecture that the earth spun on its own axis as it moved around the sun was considered by the Vatican a heresy in its contradiction to long-accepted biblical passages. It was the Vatican's understanding that the sun moved around the earth, as the earth was supposedly the centre of the cosmological system. Forced to repent, Galileo spent the final eight years of his life in prison. Although Galileo's theory proved true in the following century, the Vatican formulated an official apology and recognition of his efforts later in 1992. Such was the result of an established institution's difficulty in dissociating faith with an ancient cosmology.
A principle mechanism in scientific censorship is the requirement by the fraternity that discoveries be published in refereed, scientific journals of irreproachable standing. The referees are appointed by the editor to review proposed publications for their 'worth'. Referees or official reviewers are frequently partisan when they are informed, and just as often, they are ill-informed in regards to sub-specializations in which they have no working experience. The referee gains a sense of power in his rejections.
All systems of thinking, scientific or otherwise, have points of inflexibility even if it is the assumption that the establishment is biased. All journals, except those who no one want to write for, have the problem of selection, i.e discrimination and therefore can be accused of some form of censorship, given a loose and very abstract meaning of the word.