The Philosophy of Time

13 April, 2016 (Week1)

Michael De, University of Konstanz

Introduction

Logistics

Introduction

Aristotle on fatalism (in De Interpretation 9)

Again, if it is white now it was true to say earlier that it would be white; so that it was always true to say of anything that has happened that it would be so. But if it was always true to say that it was so, or would be so, it could not not be so, or not be going to be so. But if something cannot not happen it is impossible for it not to happen; and if it is impossible for something not to happen it is necessary for it to happen. Everything that will be, therefore, happens necessarily. So nothing will come about as chance has it or by chance; for if by chance, not of necessity. [18 b 9 ft] in [Ackrill, 1963, pp 50-51].

Fatalism

  1. Either it will rain tomorrow or it won't
  2. Suppose it will rain. Then it's true now that it will rain, so it's true of necessity.
  3. Suppose it won't. Then it's true now that it won't, so it's true of necessity.
  4. Therefore, it's either true of necessity that it will rain, or it's true of necessity that it won't.

Divine foreknowledge and fatalism

  1. For every proposition p, God knows whether or not p
  2. In particular, then, God knows whether or not it will rain
  3. Whatever God knows, he knows of necessity
  4. So if God knows that it will rain, he knows of necessity that it will rain
  5. But then if he knows that it will rain, it couldn't have been any other way, and likewise if he knows that it won't rain
  6. In either case, it couldn't have been any other way

Determinism

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 one 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 but a feeble outline of such an intelligence. [Laplace 1820]

A rough formulation of determinism

Persistence

A puzzle about persistence

Some solutions, in brief

  1. Deny Leibniz's Law. Perhaps reformulate it, e.g. to: two things are identical at a time x iff, at x, they share all their properties.

Readings

Readings

For next week, please read