Before going ahead with this I suppose that I should point out that I have no qualifications in any of the related fields. In order to make this a short introduction I have grossly simplified various arguments and avoided technicalities.
One of the interesting questions which comes out of any system for foretelling the future is where does the knowledge of future events come from ?
This is another way of asking whether these are predictive or divinatory.
Divine inspiration, vibrations from the querent, the astral plane ?
During a reading the querent is told about a situation that they would rather avoid. As a result they take steps to change their behaviour.
What will happen ? Show of hands for each scenario.
a. the situation will happen just as it was foretold regardless of what the querent does. (determinism)
b. by changing their behaviour the querent will avoid the situation. (free will)
Those who went for the first answer are demonstrating a belief in a fixed, or determined, future.
Those who went for the second answer are demonstrating a belief in free will.
Welcome to the classical argument of Freewill v. Determinism
This is an argument which weaves its way through the fabric of our society and has been discussed in various forms for over two and a half thousand years so let's start with a quick look back through history.
The Classical World
The ancient Greeks believed in a "sensible" universe, that is :-
the only things which exist are those which are detectable by the five senses. Everything else is the work of God.
The Greeks believed in divination which was performed in a religious environment such as the oracle at Delphi. The querent would write down their question and this was relayed to the pyhthoness in her sanctum where she would enter a trance like state in order to divine the answer. The answers were notoriously vague and required interpretation. When this part of the process went astray it led to some classic mistakes.
In Greek tragedy it is determinism which adds the poigniant edge to the central characters efforts to avoid his fate. When Eidopus is told that he will murder his father and marry his mother it seems ridiculous but...
we get to watch the story unfold already knowing what will happen. The audience does not have to work out what the result will be, that is taken for granted, rather the interest of the audience is engaged in trying to work out how the result will be arrived at.
It may be a sweeping generalisation but it looks like the ancient Greeks, at least in terms of Drama and Religion, believed in a fixed future or determinism.
The Medieval World
The Catholic church was against determinism as it would remove the choice to sin. If you didn't have the choice to sin then why would you need confession.
It also believed that the future belonged to God alone and that the predictive arts should be discouraged.
Thou shalt not suffer a witch to live is a mistranslation; the word meant sorcerer in the sense of a diviner. There again, it should be no surprise that this word was used given that it was James I/VI that commissioned this version of the Bible and his personal experiences of witchcraft.
According to the Malleus Maleficarum only three forms of divination are listed, these being Necromancy, Astrology, and Oneiromancy (dream interpretation)." This would suggest that either no other forms of divination existed at the time or that they were unknown to the inquisitors which would seem pretty unlikely. Why mention this ? It may be worth bearing in mind when considering the supposed antiquity of various modern divinatory techniques. Particularly the origins of the tarot.
The Renaissance
The development of the idea of a mechanistic universe.
Copernicus - the Earth is no longer the centre of the universe. The implication is that the Earth is no longer unique and that therefore there was the possibility that humans were no longer unique.
- acceptance that there are forces at work which we cannot perceive via the senses e.g. gravity, magnetism, electricity.
- these forces displace God from his hands-on role with humanity.
- the idea that God created the earth, wound it up, let it go, and then followed a course of non-interference. This is a half-way house argument but few would have been brave enough to suggest that God had nothing to do with it because this would have upset the church...
Which leads us to
The Enlightenment
and the idea of a mechanistic universe.
Sir Isaac Newton formulated his theories of motion which are meant to apply to everything from the atoms to galaxies. It is from these that we get the expression "for every action there is an equal and opposite reaction". This leads to the idea of Causality - each cause has an effect and every effect is the result of a cause. As a quick example try this :-
If I let go of my pint it will fall, due to gravity, until it hits an immovable object, the table/floor/some poor sod.
Cause - gravity and human negligence, effect - a mess on the floor.
Causality implies that any action will have a predictable result. Unless we can show that an uncaused effect exists then this means that we live in a pre-determined universe. Taking this idea a bit further leads to the idea that causality meant a fixed future, determinism.
Please note that God is no longer the cause of events which was a bit troublesome for the religious communities.
To make matters worse some bright spark decided to apply this theory to us, human society. Since everything in our universe will have a predictable result everything that we are and do is pre-determined, our lives are the result of a series of events. We have no choice and therefore no free will. When we are faced with a choice we base our decision on our experience and therefore the outcome is already decided by what has gone before.
Many people were appalled at the idea that humans could be considered mechanistic.
By this time the religious communities were livid.
The Victorian Era
All of this may seem rather intellectual but it is applied in our society. One of the logical applications of this argument is that a criminal breaks the law because he has no choice, it is pre-determined and therefore it is pointless punishing the criminal since they did not choose to commit the crime. This may seem far fetched but it is the idea behind our penal system. Those who believe in free will consider the penal system as a punishment and thereby a deterrent, those who believe in determinism see the penal system as correctional institutions.
The Modern Era
What is it that does the determining ?
Genetics (DNA) and environment.
The genetics are pretty much fixed but the environment can change.
The environment includes our education and upbringing.
We are also subject to the laws of our society, peer pressure, and the concept of acceptable behaviour to name but a few external influences.
Cultural context
From Western books and movies we have the attitude "a man's gotta do what a man's gotta do."
If anyone has seen the movie trilogy The Matrix you should be well acquainted with this argument. The Frenchman states the case for causality and the Oracle seems to play out the same scenario with the caveat that it is only as far as the unmade choices which allows for free will.
Implications of Determinism
Not a good day for philosophy as it effectively killed both god, by implication, and moral philosophy since if we do not have the free will to make a choice it is impossible to argue about whether we are acting to produce a beneficial result.
Good news for science since experimentation depends on predicting the result.
It is also good news for the predictive arts; astrology, tarot, divination.
Language
The difference between being offered a choice and making a choice (deciding).
Too much choice
A man walks into a bar. There is a huge choice of alcoholic drinks.
When is a "choice" not a choice ?
When I go to the bar I am faced with a large choice of alcoholic drinks.
So I have lots of choice. Or do I ?
Regardless of which alcoholic drink I choose the result is that I will become intoxicated.
So if a choice leads to the same result was there really a choice offered ?
Let's say that sometimes there are a range of options but no choice.
In this case the real choice would be between having an alcoholic drink or not.
Or between going into the bar or not, though the implications would be wider.
An odd situation
There is also the difference between being offered a choice and making a choice (deciding).
I walk into a bar. What do I order ?
If it's the Meadow Bar I order cider.
If it's the Diggers I order heavy.
If it's Thompson's I order IPA.
If it's the Moulin I order Braveheart.
If it's the Dagda I am confused.
Evidently there is something else going on here. There is no lack of choice being offered.
If I am choosing it is according to the environment. It is habit or experience.
Freedom of Choice
In a deterministic world you are offered a choice but the deciding is already done.
With free will you are offered a choice and you decide by . . .this may be one of the few occasions where the expression "God knows" would be appropriate.
Making a Choice
When we make a choice it may well be determined but that does not mean that it is arbitrary. We decide according to our own set of rules and principles. Some of these rules and principles may be moralistic, some practical, and some genetic.
The possibility exists that we are not acting according to free will but reacting to circumstances.
going back to the initial question and applying this it would seem that option B is not an exercising of free will but a reaction to changed circumstances and not to react would be a bit silly.
If you believe in prediction then you would probably change your behaviour.
If you don't believe in prediction then it wouldn't matter.
The Real World
So much for the theory, what happens in the real world ?
If determinism is real then it would be a bit of a problem, none of the following would exist :-
bookies
insurance
pensions
the stock market
and every weather forecast would be 100% reliable.
Religions around the world continue to flourish even although ideas such as sin and karma are dependent on free will.
I don't think that anyone would be taken seriously if they suggested that we are not responsible for our own actions.
Clearly in the real world although we may accept that causality and determinism exist they are not the whole answer.
Prediction
See "The Ascent of Science" section regarding predicting the movement of molecules.
Scientists worked out that in a fixed space it was possible to predict the movement of molecules if you know their starting point and trajectory. This led to the belief that if you knew the starting point of the Big Bang you could then predict everything which would happen thereafter. However once they took into account collisions with other molecules they discovered that they couldn't calculate the position of each molecule beyond the first collision without the aid of some very serious computing power.
Science does not dismiss prediction, it just thinks that we currently do not have powerful enough tools. Given the complexity of a human and the complexity of our social environment we have a question of scale. Theoretically it is possible to predict what will happen but it would take enormous amounts of data and computing power just to figure out whether I will have a pint of beer or a pint of cider next. To put it more diplomatically they believe that prediction is possible in theory but not in practice.
Conclusion
The philosophers killed philosophy and god.
The scientists killed prediction.
Not a good result for determinism.
Why does any of this matter ?
Well, apart from the implications for divinatory systems there is a more fundamental consideration for pagans and that is in relation to the idea of "An it harm none, do as though will". Going back to the beginning if we are the slaves of determinism then we have no free will and therefore this instruction would be irrelevant.
I'd just like to finish with a quote attributed to William of Ockham a 14th century philosopher.
"the scheme that explains the observed facts in the simplest possible way is the most likely to be correct."