Analysis of information sources in references of the Wikipedia article "Font primària" in Catalan language version.
[I]t is through the primary sources that the past indisputably imposes its reality on the historian. That this imposition is basic in any understanding of the past is clear from the rules that documents should not be altered, or that any material damaging to a historian's argument or purpose should not be left out or suppressed. These rules mean that the sources or the texts of the past have an integrity and that they do indeed 'speak for themselves', and that they are necessary constraints through which past reality imposes itself on the historian.
The same chronicle can be a primary source for the period contemporary with the author, a secondary source for earlier material derived from previous works, but also a primary source when these earlier works have not survived
[T]he term 'primary' inevitably carries a relative meaning insofar as it defines those pieces of information that stand in closest relationship to an event or process in the present state of our knowledge. Indeed, in most instances the very nature of a primary source tells us that it is actually derivative.…[H]istorians have no choice but to regard certain of the available sources as 'primary' since they are as near to truly original sources as they can now secure
The analysis of secondary source information is problematic. The further an investigator is from the primary source, the more distorted the information may be. Again, each new person may put his or her spin on the findings.
