Wednesday, 14 January 2015

A Defence of Two Basic Principles (Part I)

Last year, I had the honour of debating Travis McKenna of the University of Sydney Atheist Society on the question of whether God exists. I had nothing particularly original to offer, I defended the argument, which St. Thomas calls the most evident, namely the argument from motion. Travis responded in a way which, I'll admit, caught me somewhat by surprise, in that he directed most of his criticism on a single point, namely the Principle of Causality. Since then, I've been intending to write a series of blog posts on Causality, and it's related principle, the Principle of Sufficient Reason.

The Principle of Causality (PC) and Principle of Sufficient Reason (PSR) were once generally accepted as basic rules of metaphysics. Since the time of the Scottish philosopher David Hume (1711-1776) however, they've been highly controversial. I shall be arguing, however, that they are reliable principles from which knowledge can be derived.

Definitions

St. Thomas defined the PC: "nothing can be reduced from potentiality to actuality, except by something in a state of actuality." While I like this definition, it has a certain amount of baggage in that it's tied to some Aristotelian views on potentiality and actuality. Since I want to keep the discussion here relatively focused, for the purposes of this series, my definition of the PC shall be "Whatever is changed in any way is changed by something other than its self."

The PSR, like the PC has been formulated in a variety of different ways. For  the purposes of this series, however, we can define the PSR as this: "Whatever exists has an explanation for its existence either in its own necessity or in some external cause."

For some these two principles may seem simple common sense after all, in our common experience, things don't generally pop into existence without explanation.  Philosophically, however, simple common sense  is not enough. Even if we could, simply accept these principles as matters of common sense in describing interactions between things in our world, that would be insufficient to  justify the use of such principles in arguments for God's existence. After all, the fact of these principles holding good in this universe wouldn't prove that they hold in relation to something outside of the universe.

This Series

What I hope to show with this series, however, is that the PC and PSR have more than just common sense and empirical data behind them but are necessary truths about all possible existence. My plan is to start by looking at the nature of an  axiom, then by examining why the PC and PSR should be considered axioms, then by looking at some common objection.