Determinism

[Purple Rabbit]

Determinism means the future is determined which means there is only one possible future - if there was more than one possible future then it isn't determined.

I'm talking about philosophical determinism not scientific determinism. As I said, indeterminacy and determinacy in science are perhaps another matter altogether.

There is no difference in the way that philosophy and science define causal determinism. If you claim that, please let me know what this difference is. In the definition that is. Also, please observe that the quote I gave was from the Stanford Encyclopedia of Philosophy. It is true however that science and philosophy have another angle of approach to the problem. In trying to establish whether our reality is causally determined science and philosophy follow different paths. Philosophical arguments, like that of Dennett, try to establish from argument and experience whether determinism holds. Dennett puts on top of that the question if it in the end matters to us? Scientific arguments try to show that there is a description of nature that is fully causal, i.e. a description that fully describes all phenomena of reality if all inputs were known. Dennett's argument is of the kind that it in the end has no impact on what we perceive as human freedom whether the physics is fully causal or not. For instance he argues that randomness, if it truly exists in nature, does not amount to freedom at the level of human perception.

Determinism in science I believe refers to the predictability of the future, which has got nothing to do with philosophical determinism which just means that the future is fixed, determined, whether we can predict it at all or not. Philosophical determinism just means there is only one possible future.

As I've said, the definitions of causal determinism are the same for science and philosophy but only their methods of proof differ. Predictability often is used to describe the concept of determinism in both cases.

Wikipedia: "Determinism is the philosophical view that every event, including human cognition, behavior, decision, and action, is causally determined by the environment. It is, in essence, the view that one's life is predetermined before one is even born. Determinism proposes there is a predetermined unbroken chain of prior occurrences back to the origin of the universe."

If the future is predetermined from the start and layed out, then by definition there can't be any more than one possible future: therefore there is one possible future. Only one possible future=determinism.

The Wiki quote shows that there is no tenet about one possible future. Causal determinism (= philosophical understanding of determinism = scientific understanding of determinsim) does not necessarily mean that the future is fixed in the sense of one possible future. The catch here is in the word "necessarily". On first examination it seems that causal determination, defined as above, indeed should mean that there is only one possible future, for if every event has specific causes, how can that lead to multiple outcomes? But the point is that the term "possible future" is a rather vague one. Does it mean something like "possible for us to live in" or "possible to exist" or something else still? In the Everett Many Worlds model multiple realities co-exist with each other, yet in any particular history of events in the Everett Many Worlds model (EMW) causal determinism holds. To understand its implication it is not necessary to know anything of quantum mechanics, the theory that led to the fomulation of EMW. The important thing is that causal determinism does not necessarily mean "one possible future" in a strict sense. Please note however that I am not saying here that the EMW model is the final description of reality. The jury (as in Mother Nature) is still out on that one. But as a model it shows that determinsim does not necessarily imply "one possible future".

You can observe from this definition that it does not claim "one possible future"

It doesn't need to though does it? It just has to imply it. And it absolutely does imply it: If the future is completely predetermined and fixed, then there is only one possibility of what it will be: the way it is fixed, predetermined, to be.

This is where you should adjust your reasoning. The EVM model refutes the argument you're making.

The way I define it as meaning "only one possible future" is how Daniel Dennett defines it by the way...

Determinism, according to Dennett, is the thesis that ''there is at any instant exactly one physically possible future''

Does Dennett embark on the EVM model? I have "Freedom Evolves" with me here but can't find a single line in it on the subject . All Dennett says about quantum mechanics is that quantum indeterminacy does not yield free will. He nowhere to my knowledge embarks on the Many Worlds hypothesis. And he need not, for his argument, which I fully comply with, is that human freedom does not depend on either quantum indeterminacy or full causal determinacy.

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@Caecilian

I'm just talking about causal determinism, nothing else. I think economic and linguistic determinism loosely borrow on that concept but are quite different from causal determinsim.

Genetic determinism I'm not quite sure of. But if you are referring to the nature vs nurture debate IMO it is a mistake to attribute genetic determinism (~nature) to Dawkins and Dennett. Both gentlemen acknowledge that the genetic makeup is not enough to explain human behaviour.