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Classical Determinism is the thesis that every event is determined by laws of nature and antecedent conditions.

Table of Contents

1. Classical Determinism
2. Pierre Laplace, from A Philosophical Essay on Probabilities, 1814
3. How Classical Determinism Works
4. Incompatibility of Determinism and Categorical Free Will
5. Addenda
   1. Formulations of Classical Determinism

Classical Determinism

Classical Determinism is the thesis that every event is determined by antecedent conditions and the laws of nature.

Pierre Laplace, from A Philosophical Essay on Probabilities, 1814

“We ought to regard the present state of the universe as the effect of its antecedent state and as the cause of the state that is to follow.  An intelligence knowing all the forces acting in nature at a given instant, as well as the momentary positions of all things in the universe, would be able to comprehend in a single formula the motions of the largest bodies as well as the lightest atoms in the world, provided that its intellect were sufficiently powerful to subject all data to analysis; to it nothing would be uncertain, the future as well as the past would be present to its eyes. The perfection that the human mind has been able to give to astronomy affords a feeble outline of such an intelligence. Discoveries in mechanics and geometry, coupled with those of universal gravitation, have brought the mind within reach of comprehending in the same analytic formula the past and future state of the system of the world.  All the mind’s efforts in search for truth tend to approximate to the intelligence we have just imagined although it will forever remain infinitely remote from such an intelligence.”

How Classical Determinism Works

• Suppose that two 16-pound bowling balls are motionless 10 meters apart in otherwise-empty intergalactic space. 
• What happens to the balls is determined by antecedent (initial) conditions plus the laws of nature.
• Antecedent conditions:
  • The mass of ball A is m₁ = 7.25748 kg and its center is located at point x₁ = 0 meters on the x-axis
  • The mass of ball B is m₂ = 7.25748 kg and its center is located at point x₁ = 10 meters on the x-axis
• Applicable laws of nature:
  • Law of Universal Gravitation: For any pair of physical bodies there’s a force on each, toward the other, with magnitude Gm₁m₂/r²
    • where G = 6.67384 10^-11 (the gravitational constant), m₁ and m₂ are the masses of the bodies, and r is the distance between them
    • Abbreviated F=Gm₁m₂/r²
  • Equation of Motion: The acceleration a physical body undergoes equals the net force on the body divided by its mass
    • Acceleration is how fast or slow the velocity of a body changes
    • Abbreviated A = F/M
• The antecedent conditions and laws, through the magic of differential equations, logically entail that the bowling balls accelerate toward each, colliding in 13 days.

View Animation of Predicted Motion of Bowling Balls
View Magic of Differential Equations

Incompatibility of Determinism and Categorical Free Will

• Argument for Incompatibility
  • If determinism is true there are events occurring before a person is conceived that, in conjunction with the laws of nature, logically entail what they do.
  • A person cannot prevent or undo events occurring before they are conceived.
  • A person cannot violate or undo the laws of nature. 
  • Whatever is logically entailed by things beyond a person’s control is itself beyond their control.  
  • Therefore, if determinism is true, whatever a person does is beyond their control and something they could not have avoided doing.

Addenda

Formulations of Classical Determinism

• Leucippus, fifth century B.C
  • “nothing occurs at random, but all things for a reason and by necessity.”
• Pierre Laplace, 1814
  • “We ought to regard the present state of the universe as the effect of its antecedent state and as the cause of the state that is to follow.  An intelligence knowing all the forces acting in nature at a given instant, as well as the momentary positions of all things in the universe, would be able to comprehend in a single formula the motions of the largest bodies as well as the lightest atoms in the world, provided that its intellect were sufficiently powerful to subject all data to analysis; to it nothing would be uncertain, the future as well as the past would be present to its eyes.”
• C.S. Peirce, early 20th
  • “The state of things existing at any time, together with certain immutable laws, completely determine the state of things at every other time.”
• C.J. Ducasse, mid 20th
  • “On the basis of knowledge of (a) the state of the world at any given time and (b) the laws according to which its state at any time is related to its states at other times, it would be possible to infer what the state of the world was, or will be, at any earlier or later time.
• Alvin Goldman 1970, 172
  • Every event e is such that a proposition asserting that e occurs (at t) is deducible from some conjunction of (true) propositions describing laws of nature and events prior to t (but not deducible from propositions describing prior events alone).
• Bernard Berofsky 1971
  • (x)[x is an R-sentence –> (Ey)(Ez)(y is a state-description-sentence & z is a law-sentence & -| (y & z) –> x)].  An R-sentence is true, contingent, singular, and temporal. 
• Nicholas Denyer, 1981
  • For every stage of the universe there are truths about that stage which, together with some law or conjunction of laws, entail a complete description of every later stage of the universe.
• Peter van Inwagen 1983, 65
  • For every instant of time, there is a proposition that expresses the state of the world at that instant; If p and q are any propositions that express the state of the world at some instants, then the conjunction of p with the laws of nature entails q
• John Earman 1985, 13
  • Letting W stand for the collection of all physically possible worlds, that is, possible worlds which satisfy the natural laws obtaining in the actual world, we can define the Laplacian variety of determinism as follows.  The world W e W is Laplacian deterministic just in case for any W’ e W, if W and W’ agree at any time, then they agree for all times.  By assumption, the world-at-a-given-time is an invariantly meaningful notion and agreement of worlds at a time means agreement at that time on all relevant physical properties.
• plato.stanford.edu/entries/determinism-causal/
  • Causal determinism is, roughly speaking, the idea that every event is necessitated by antecedent events and conditions together with the laws of nature. The idea is ancient, but first became subject to clarification and mathematical analysis in the eighteenth century. 
• britannica.com/topic/problem-of-moral-responsibility#ref284014
  • Determinism  is the view that, given the state of the universe (the complete physical properties of all its parts) at a certain time and the laws of nature operative in the universe at that time, the state of the universe at any subsequent time is completely determined. No subsequent state of the universe can be other than what it is.
• merriam-webster.com/dictionary/determinism
  • a theory or doctrine that acts of the will, occurrences in nature, or social or psychological phenomena are causally determined by preceding events or natural laws
• ahdictionary.com/word/search.html?q=determinism
  • The philosophical doctrine that every state of affairs, including every human event, act, and decision, is the inevitable consequence of antecedent states of affairs.