When people say that that fatalism is true, they may have different things in mind.  For example, they might mean that events happen with logical or metaphysical necessity, or even merely that events are determined (determinism).  However, here we follow Cahn's definition of fatalism as the view that the laws of logic, by themselves, as sufficient to show that nobody has free will.  Of course, this requires explaining what free will consists in.  There are two views of the nature of free will:

• agent causation, which entails the capacity to do otherwise than one does, i.e. having the power to act differently than one does
• being able to do as one wants.

A. Argument for fatalism:
 Let t₀, t₁, and t₂ be successive times.  Then:

1. The tenseless view of time entails bivalence, i.e. that every statement is either true or false, because in this view all events are 'eternally' spread out in the dimension of time: they all coexist, although, of course, they are not all simultaneous

NOTE: by contrast, the tensed theory of time is merely compatible with bivalence.  Hence, what follows may, but need not, apply to the tensed view.
2. Hence, "A sea battle takes place at t₂" (P), uttered at t₀ is either true or false at t₀
3. If P true at t₀, then a sea battle takes place at t₂; if P false at t₀, it does not.
4. Hence, nothing can be done at t₁ to change what happens at t₂ because what happens at t₂ depends on the truth or falsity of P at t₀, and nothing can possibly happen at t₁ to change the truth value of P at t₀.  So, nobody at t₁ has the power to act differently than one acts at t₂
5. Hence, fatalism is true.

B. Possible problems with the argument:

Problems with (2):

• A statement is not true or false at a date.  Hence it isn't true that P is true or false at t₀; so, (4) is false because P is not true earlier than t₁.

Problem: P is a token, an utterance, and as such it is dated (it must occur at a date).  Hence, it must have its truth value at that date, i.e., at the date it exists.
• Analyses of what makes P true at t₀:
1. P's truth at t₀ depends on the relevant state of affairs at t₂ , the time it refers to.  Hence, what happens at t₁ can affect what happens at t₂, which is the reason for P's truth or falsity at t₀. So, (2-3) don't lead to (4)
2. P's truth at t₀ depends on the relevant state of affairs at t₀, the time it is uttered at.  Hence, the fact that at t₂ a sea battle takes place (or not) is the case at t₀.  So, (2-3) do lead to (4)

Objections:
• Meta-facts (the fact that a fact is the case, or that an event occurs at a date t) do not exist; we can say "it is a fact that fact F is the case," but we are just restating "fact F is the case."
• Meta-facts exist but not at any date, i.e. not in the B-series.  If so, there is no meta-fact at t₀ making P true at t₀.  Meta-facts are eternal in the sense specified below.

Reply: Merely ad hoc reply?  What’s the independent rationale for denying that meta-facts are in the time series?

(4) assumes that I cannot affect the past, not even in the sense that the truth value of P  is up to me.  But that P is true (suppose) is not a past event (which the direction of causation prevents me from affecting) but a past fact that  obtains because of  future event, which I can affect.  Hence, A’s argument  seems to confuse facts (e.g. that P is true) with events (e.g. what makes P  true).

1. Eternity₁: sempiternity, i.e., existing at each time.  For example, the law of conservation of energy seems to entail that energy/mass is eternal in this way.

NOTE: Detensers deny that sea battle or meta-fact about it are sempiternal.
2. Eternity₂: totally independent of time because a thing eternal in this sense is not in time, doesn't exemplify temporal items, and doesn't involve temporal items.  For example, Augustine thought of God in this way; probably Plato thought of Forms and their relations this way.

NOTE: Meta-facts involve temporal items (i.e. facts or events); hence, they are not eternal₂.
3. Eternity₃: dependent on time because it involves temporal items; however, things which are eternal this way are not in time.  For example, meta-facts, including the fact that the whole B-series is the way it is, are eternal₃.

Objection: what reasons are there for introducing Eternity₃, apart from avoiding fatalism?

Cahn: Fate, Logic, and Time

While the best argument for fatalism depends on the tenseless view of time, the classic arguments for fatalism, of which Aristotle's is the best known, move from a tensed view of time, and take advantage of the fact that bivalence is compatible with the tensed view of time, although it is not entailed by that view.

A.  An “Aristotelian”  argument which is the tensed version of the tenseless argument above:

1. Every statement P must be either true, or, if not true, false (principle of bivalence).
2. P = “ a sea battle will take place tomorrow.”
3. Hence, either P is true, or if not true, then false.
4. So, it must already be true now that a sea battle will take place tomorrow or false now that a sea battle will take place tomorrow.
5. If it is true now that a sea battle will take place tomorrow, then nobody can bring about that it might not; and if it is true now that a sea battle will not take place tomorrow, then nobody can bring about that it might.
6. Hence, the future is fated.

1. non-contradiction: If P true, then not-P false, and if not-P true, then P false.
2. excluded middle (analytic): “P or not-P” is a logical truth (a tautology).
3. excluded middle (synthetic or bivalence): P is true, or, if not true, then false.

• Propositions have 3 truth values: "true", "false" or "indeterminate".  In our case, propositions about future contingents have truth value "indeterminate".
• The Principle of non contradiction preserved because if P true, then not-P false and viceversa.  Hence, vacuously true of future contingents, which are neither true nor false
• If P undetermined, then not-P indeterminate as well.
• The Principle of excluded middle (analytic) preserved because “P or not-P” necessarily true (either the sea battle will occur or not).
• The Principle of excluded middle (synthetic) rejected b/ecause if P not true, then not-P needn’t be false since P could be undetermined.

• Propositions change truth values because propositions about future contingents are indeterminate today, but true (or false) the day after tomorrow.  Hence, the idea (Russell, Quine etc.) that truth values are unchanging must be rejected.

NOTE: in particular while I can change the truth value of a proposition about a future contingent (by mowing the lawn now I can change the truth value of "I'll mow the lawn" from indeterminate to true), I cannot change the truth value of propositions about the past.
• The extrinsic modalities of propositions (ex. falsifiability) change with the passing of time: propositions about future contingents are falsifiable but propositions about the past are not.
• The tenseless view of time must be rejected because propositions must change truth value, and in the B series they cannot.
• The flow of time (as in the A series) is efficacious because it affects the truth-value of propositions.  Hence, time is real, contra McTaggart, Augustine, etc.
• The future is different from the past because not only does it come later, but it also contains possibilities which are not in the past.