Talk:Causality

The topics "causality" and "causation" should be a "pointer page," if in fact there is a significant body of physics research about causality, that should properly be so titled. There is, of course, a very old tradition of analyzing the notion of causality in philosophy, which continues robustly to this day; philosophers, to my knowledge, don't pay much attention to what physicists have to say on the topic, but then, this isn't my area. Anyway, if indeed there is a body of physics research into causality per se, then we might have a causality (physics) page as well as causality (philosophy) or causation (philosophy) page. In any case, it's certainly the case that what physicists have said on the topic should not be billed as the only thing Wikipedia has to say on the topic.

Speaking as a philosopher, not as a physicist, the following looks like a lot of pseudoscientific, pseudophilosophical rubbish to me. I'm familiar with Osher Doctorow from Nupedia, and I have serious doubts that anything from him deserves such prominent mention in any Wikipedia article. As for the physics, there might be something salvagable in it--for all I know, it's a good start, but I know nothing about physicists' approach to this otherwise purely philosophical topic, so I couldn't say. In the meantime, I'd like to request that a physicist (other than Osher Doctorow) have a look at this and give his or her opinion. --Larry_Sanger

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Causality or causation in mathematics/physics may be considered to have begun its modern treatment by Professor Garrett Birkhoff of Harvard in the 1950s, who considered that causation is embodied in time-related differential equations (ordinary or partial) because they involve time and because they involve change through time whereby intuitively an independent variable x or t influences a dependent variable y, although derivatives/rates of change of y with respect to time (velocity, speed, acceleration, etc.) may also do the influencing.

Although David Hume in the 1700s had given up on the possibility of locating the exact connection involved in causality/causation, Birkhoff felt that differential equations involving time embody what (in historical/philosophical language) Hume had been trying to analyze. In reply to the question of how the influencing variable x at time t influences variable y at an immediately later time, which of course is in a sense incapable of formulation since there is no immediately later event, Birkhoff's PDEs (partial differential equations) and ODEs (ordinary differential equations) rely on limits, noting that lim [f(t + h) - f(t)]/h as h--> 0, when it exists, is the derivative f'(t), which is the instantaneous rate of change of f at time t, but can also be regarded as the influence of time t on an infinitesimally small increment f(t + h) when h is positive but approaches 0 (from the right). Although the approach to 0 from the left seems to complicate things, it does not change the above facts.

The next major step forward in causation/causality was its application to probability-statistics by Marleen and Osher Doctorow, in their paper "On the nature of causation", (Philosophy of Education Proceedings 1983), based on seminars and talks in the previous years in part, in which they formulated a probability-statistics criterion for causation/causality. See abstracts of 72 of their papers (publications, papers presented, technical reports, and some better internet contributions) at http://www.logic.univie.ac.at, Institute for Logic of the University of Vienna. After accessing the site, select in this exact order:

ABSTRACT SERVER

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Doctorow, Osher and/or Doctorow, Marleen