Serious objections have been raised to the idea that we have free will.

Several systems of thought have claimed that man isn't free, that everything he does follows well-determined laws. Hence the name “determinism.” Fatalism and determinism have often (and mistakenly) been confused. Fatalism assumes that all beings depend on a higher will that's omnipotent but also arbitrary and capricious. This assumption lay behind the ancient notion of fatum, or fate, as well as the Mohammedan notion of destiny. But fatalism has since fallen away, and we needn't refute it here.

The key argument of determinism is the irreconcilability of free choice and the principle of causality. Some determinists, wanting to demonstrate this alleged irreconcilability without leaving the world of inner experience, have tried to identify fixed psychological laws that govern our actions. Others have pointed to the contradiction between the principle of causality, as used in science, and the principle of freedom.

Today we'll discuss psychological determinism.

Here's an action: I go outside. Why? Because my health requires me to exercise, or because there's some task I must perform. These are the causes of my action, the motives that lead me to it. And because my action has a cause, it's not free. Freedom is only an illusion.

Determinists go on to pose the following dilemma:

• either the act we thought free was actually caused by a motive and thus wasn't free; or

• it didn't have any cause at all – which violates the principle of causality.