We must carefully disambiguate causality from its close relatives certainty, determinism, necessity, and predictability.

Although philosophers almost all became language philosophers in the twentieth century, they have been notoriously sloppy with definitions of philosophical terminology. They have been especially confused when they attempt to prove things with logic and language about the world.

For example, they like to say that if determinism is false, indeterminism is true. The situation is much more complex than such simple black and white thinking.

The core idea of causality is closely related to the idea of determinism. But we can have causality without determinism. We call it "soft" causality. And we will see that the departure from strict causality is very slight compared to the miraculous ideas associated with the "causa sui" (self-caused cause) of the ancients.

Certainty, necessity, and predictability are all closely related to determinism, but they have their main applicability in slightly different fields - mathematics, logic, and physics - which gives rise to ambiguity when used outside those fields.

Certainty is a powerful idea that has mesmerized philosophers, and especially religious leaders, throughout the ages. Belief in absolute and certain truth has all too often justified the most inhumane behavior toward those not sharing that truth and that belief. Certainty is the limiting case of a mathematical probability.

Necessity is often opposed to chance. In a necessary world there is no chance. Everything that happens is necessitated. In our real physical world nothing is necessary. There is nothing logically true of the world. Logic is just a useful tool as part of our deductive reasoning.

Predictability is a characteristic of law-governed phenomena. When the laws are expressible as mathematical functions of time, knowledge of the initial conditions at some time allows us to predict the conditions at all later (and retrospectively earlier) times.