Formal Dictionary

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The Ethics by Baruch Spinoza is an inspiration for this project.

The Formal Dictionary is a growing collection of definitions that are sufficiently formal to be used in formal proofs.

You can transclude the terms in this dictionary and use them to prove theorems and build theories.

If you want to contribute, check out the guidelines first.

Definitions[edit]

Accessibility relation[edit]

Accessibility relation is a primitive term, an undefined term used to define others. You can get an intuitive grasp of the intended meaning of the term by reading the Wikipedia article Accessibility relation.

Accidental property[edit]

Let P be a property, x an entity and w a possible world. Then P is an accidental property of x in w means: x has P in w, but in at least one possible world, x exists without P.[1]

Actual property[edit]

Let P be a property, x an entity and w a possible world. Then P is an actual property of x in w means: P is a property of x in w.

Aristotelian change[edit]

Let x be an entity and w1 and w2 two possible worlds. Then x changes aristotelically from w1 to w2 means: there is at least one possible world w accessible from w1 and with access to w2 (or identical to w2) such that P is a potential property of x in w1 and an actual property in w.

Causal chain[edit]

A sequence of events (e1, e2, e3 ..., en) is a causal chain means: e1 is a cause of e2, e2 is a cause of e3 and so on until en-1 is a cause of en

Causal independence[edit]

Let c and e be events. Then c is causally independent of e means: c is not a cause of e and e is not a cause of c.

Cause[edit]

Cause is a primitive term, an undefined term used to define others. You can get an intuitive grasp of the intended meaning of the term by reading the Wikipedia article Cause.

Change (1)[edit]

Let x be an entity, and w1 and w2 two possible worlds. Then x changes from w1 to w2 means: there is at least one property P and at least one possible world w accessible from w1 and with access to w2 (or identical to w2) such that x has P in w1 and lacks it in w, or lacks it in w1 and has it in w.

Change (2)[edit]

Let x be an entity, and w1 and w2 two possible worlds. Then x changes from w1 to w2 means: there is at least one property P such that x has P in w1 and lacks it in w2, or lacks it in w1 and has it in w2.

Determinism[edit]

Determinism means: every possible world has direct access to exactly one possible world.

Direct cause[edit]

Let c, d and e be events. Then c is a direct cause of e means: c is a cause of e and there is no d such that c is a cause of d and d is a cause of e.

Element[edit]

Element is a primitive term, an undefined term used to define others. You can get an intuitive grasp of the intended meaning of the term by reading the Wikipedia article Element (mathematics).

Effect[edit]

Let c and e be events. Then e is an effect of c means: c is a cause of e.

Entity[edit]

Entity is a primitive term, an undefined term used to define others. You can get an intuitive grasp of the intended meaning of the term by reading the Wikipedia article Entity.

Essence[edit]

Let x be an entity. Then the essence of x is the set of all its essential properties.

Essential property[edit]

Let P be a property and x be an entity. Then P is an essential property of x means: in every possible world where x exists, x has P.[1]

Event[edit]

Event is a primitive term, an undefined term used to define others. You can get an intuitive grasp of the intended meaning of the term by reading the Wikipedia article Event (philosophy).

First cause[edit]

Let e be an event. Then e is a first cause means: there is no event c that is a cause of e.

Full set of causes[edit]

Let e be an event and ε be a set of events. Then ε is a full set of causes of e means: for every event c that is a cause of e, c is an element of ε.

Identity[edit]

Let x and y be two entities. Then x and y are identical means: they have the same properties.

Indirect cause[edit]

Let c and e be events. Then c is an indirect cause of e means: c is a cause of e, but c is not a direct cause of e.

Metaphysical probability[edit]

Let p be a proposition, w a possible world and n a real number between 0 and 1. Then the metaphysical probability of p in w is n means: the number of possible worlds accessible from w where p is true divided by the total number of possible worlds accessible from w equals n.

Note: we assume that the total number of possible worlds accessible from w is a finite number, else all metaphysical probabilities collapse to zero.

Object[edit]

Object is a primitive term, an undefined term used to define others. You can get an intuitive grasp of the intended meaning of the term by reading the Wikipedia article Object.

Possible world[edit]

Possible world is a primitive term, an undefined term used to define others. You can get an intuitive grasp of the intended meaning of the term by reading the Wikipedia article Possible world.

Potential property[edit]

Let P be a property, x an event and w a possible world. Then P is a potential property of x in w means: x exists without P in w, but in at least one accessible possible world, x has P.

Property[edit]

Property is a primitive term, an undefined term used to define others. You can get an intuitive grasp of the intended meaning of the term by reading the Wikipedia article Property.

Sequence[edit]

Set[edit]

Set is a primitive term, an undefined term used to define others. You can get an intuitive grasp of the intended meaning of the term by reading the Wikipedia article Set (mathematics).

Supervenience (1)[edit]

Let A and B be two sets of properties. Then A-properties supervene on B-properties means: all entities that are B-indiscernible are A-indiscernible.

Supervenience (2)[edit]

Let A and B be two sets of properties. Then A-properties supervene on B-properties means: anything that has an A-property has some B-property such that anything that has that B-property also has that A-property.

Theorems[edit]

Potential properties are not actual[edit]

If P is a potential property of x in w, then P is not an actual property of x in w.

Actual properties are not potential[edit]

If P is an actual property of x in w, then P is not a potential property of x in w.

Essential properties are actual[edit]

If P is an essential property of x, and x exists in w, then P is an actual property of x in w.

Potential properties are not essential[edit]

If P is a potential property of x in w, then P is not an essential property of x.

Essential properties do not change[edit]

If x changes a property P from w1 to w2, then P is not an essential property of x.

Suppose x changes a property P from w1 to w2. Then, by the definition of change, there's at least one possible world w accessible from w1 and with access to w2 (or identical to w2) where x exists, and x has P in w1 but lacks it in w, or lacks it in w1 but has it in w. In either case, there's at least one possible world where x exists without P, so by the definition of essential property, P is not an essential property of x. QED

Some changes are not Aristotelian[edit]

Theories[edit]

Guidelines for contributors[edit]

  • When adding a primitive term, use the Template:Formal Dictionary/Primitive.
  • Do not link your definitions outside of the dictionary, for example to Wikipedia. One of the goals of the dictionary is to be able to track the definitions back to the primitives. Linking out of the dictionary defeats this purpose. If you want to link to a term that hasn't been defined yet, just create a section for it and leave its definition for later, or mark it as a primitive term.
  • When defining a term, link only the first appearance of each other term to its definition in the dictionary.
  • If you want to add a different definition for an already existing term, distinguish them with numbers between parenthesis, like in Change (1) and Change (2).

Notes and references[edit]

  1. 1.0 1.1 Essential vs Accidental Properties in the Stanford Encyclopedia of Philosophy