He thought that, for any given topic, all four kinds of explanatory mode were important, each in its own right. As a result of traditional specialized philosophical peculiarities of language, with translations between ancient Greek, Latin, and English, the word cause is nowadays in specialized philosophical writings used to label Aristotles four kinds. In ordinary language, the word cause has a variety of meanings, the most common of which refers to efficient causation, which is the topic of the present article. Material cause, the material whence a thing has come or that which persists while it changes, as for example, ones mother or the bronze of a statue (see also substance theory). Formal cause, whereby a things dynamic form or static shape determines the things properties and function, as a human differs from a statue of a human or as a statue differs from a lump of bronze. Efficient cause, which imparts the first relevant movement, as a human lifts a rock or raises a statue. This is the main topic of the present article. Final cause, the criterion of completion, or the end; it may refer to an action or to an inanimate process. Examples: Socrates takes a walk after dinner for the sake of his health; earth falls to the lowest level because that is its nature.Of Aristotles four kinds or explanatory modes, only one, the efficient cause is a cause as defined in the leading paragraph of this present article.
These theories can often be seeing as "floating" their account of causality on top of an account of the logic of counterfactual conditionals. This approach can be traced back to David Humes definition of the causal relation as that "where, if the first object had not been, the second never had existed." More full-fledged analysis of causation in terms of counterfactual conditionals only came in the 20th century after development of the possible world semantics for the evaluation of counterfactual conditionals. In his 1973 paper "Causation," David Lewis proposed the following definition of the notion of causal dependence:
An event E causally depends on C if, and only if, (i) if C had occurred, then E would have occurred, and (ii) if C had not occurred, then E would not have occurred.Causation is then defined as a chain of causal dependence. That is, C causes E if and only if there exists a sequence of events C, D1, D2, ... Dk, E such that each event in the sequence depends on the previous. This chain may be called a mechanism. Note that the analysis does not purport to explain how we make causal judgements or how we reason about causation, but rather to give a metaphysical account of what it is for there to be a causal relation between some pair of events. If correct, the analysis has the power to explain certain features of causation.