nat - Chapter 19 Subjunctive Conditionals And Time's Arrow...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 19 Subjunctive Conditionals And Time’s Arrow (Plus Antecedent Relativity) § 114 Explaining the Arrow of Time Bennett’s account of subjunctive conditionals is based on Lewis’s. However, there are differences. This is the topic of Chapter 19. Lewis wants his account of subjunctive conditionals to help explain temporal asymmetry, the difference between past and future. Although Bennett uses the blanket term “time’s arrow” for the direction of time, there are a few different categories of temporal asymmetry, e.g. entropic processes, expanding light spheres, consciousness, and the dependency of the future on the past. Lewis’s account deals with the last of these. Lewis wants his analysis of subjunctive conditionals to explain our sense that the past is fixed and that there are many possible futures, which he terms the Asymmetry of Openness (AO). He also wants it to explain the Asymmetry of Causation (AC), the fact that causes predate their effects. Neither the future nor the past can change. Logically, whatever happens at a future time Tf will be whatever happens at time Tf. However, we can say that the past affects the future. A affects C : A is true, C is true, (A>(C is true. Lewis then says that C counter-factually depends on A. Earlier times affect later times because most true counterfactuals have an antecedent which concerns a time which is earlier than the time of the consequent. This is all there is to openness. A causes C if there is a chain of counter-factual dependencies of this sort which connects A and C. Bennett adds that for Lewis, causation only holds between events. Lewis thinks that it makes sense to speak of the future affecting the past in exotic situations such as sci-fi time travel, precognition, Godel topologies, etc. Presumably, in such scenarios there is a true counterfactual (A>(C, where A is later than C, and, intuitively, we judge that A causes C. The problem is that Lewis’s analysis seems to imply that the future affects the past in ordinary, everyday situations. There are true, backwards counterfactuals which we do not think involve backwards causation. These are conditionals which say that if it were the case that A, then C would have to have obtained. We covered these last week. Bennett’s example:
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
If Adlai Stevenson had been the undisputed President in February 1953, then he would have to have been elected in November 1952. On Lewis’s analysis this implies that Stevenson’s not being president in 1953 caused him to lose the election. (Note that the consequent must be on the ramp. If the consequent is before the fork, then this is a non-interference conditional, which does not display counter-factual dependency.) Lewis’s answer is that in backwards conditionals the relationship between A and C is not definite and detailed. Bennett replies that in this example, being President implies being elected in as definite
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 10

nat - Chapter 19 Subjunctive Conditionals And Time's Arrow...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online