Forces/Bigelow/Pargetter: (Lit: Bigelow, Ellis Pargetter 1988) Thesis: forces are relations and a subspecies of causal relations.
Here: stronger thesis all causes supervene on forces. Forces are higher-level relations between structures that involve individual events and their properties.
Forces/tradition: intermediary between causes and effects.
Intermediate/middle position/intermediate position/BigelowVsTradition/HumeVsTradition: Problem: Regress: if F is used as an intermediary between C and E, why is there not another mediator between F and E? Requirement for this argument is however: the assumption that C, E, and F are entities of the same type.
Wrong solution: to assume that forces are "immediate causes". For this would again require immediate causes.
Wrong solution: to construct forces as dispositional properties: either dispositions of an object for changes or a field for any effects.
Disposition/Bigelow/Pargetter: is not itself part of a causal chain. So we cannot close a gap in the chain with it. Therefore there is no threat of regression here.
Nevertheless, dispositions simply do not have the right ontological category for forces. We can give a complete causal explanation without mentioning dispositions. For the causation is given by the physical basis of dispositions.
Disposition/Bigelow/Pargetter: supervenes, but does not participate in the causal process. But they can be there if they are not active, while forces cannot do that.
Forces: take part in the causal process. If they are not active, they do not exist - unlike dispositions.
Forces/Ellis/Bigelow/Pargetter (1988): Thesis: they constitute causal relations. They are not themselves causes, but a relation between cause and effect. As a commonality between quite different phenomena.
They should also show the commonality of laws, even if they are formulated very differently.
Law/Forces/Ellis/Bigelow/Pargetter: inversely, similarly constructed laws may involve quite different forces, e.g. the proportion of the inversed square.
New/Bigelow/Pargetter: recently, we no longer identify an instance of a causal relation with a single force (see below). New: different fundamental forces join forces to form fundamental causes.
We keep the other arguments:
Forces and fundamental causes must be relations of a higher level between events, for, as a relation of first level, they would make a Humean world impossible.
Property complex/Bigelow/Pargetter: they are what is put into relation by forces. Each has as a constituent a number of properties and relations of 1st level. All will also be there in a Humean world. Only in the actual world there are the cohesive forces, and these are external relations.
Actual world/Bigelow/Pargetter: even in our world there may be other instances of these property complexes which are not in these causal relations. This is due to the local nature of the causal relations.
Stock: forces: realistic view: Bigelow/Pargetter, Ellis 1988: either the components or the resulting forces are real (not both, otherwise double causation) - Vs: Cartwright 1980, 1983)
Forces/Ellis/Bigelow/Pargetter: either, the components of forces are real or the resulting forces are real.
For example, there may be a resultant force of 0, because forces neutralize if they deviate from 0.
Problem: the components and the resulting forces cannot all be real, otherwise we would have overdetermination or double causation.
Realistic view: must be decided from case to case whether it sees the components or the resulting forces as real.
For example, we must sometimes assume different relative strengths of components to explain a resulting force.
Reality/Bigelow/Pargetter: the reality of the components is sometimes forced upon us by our considerations. For example, three protons, shielded from interference from the outside, one in the middle of a line between the other two. The predicted movement of the outer towards the outside will involve forces that exist between the two outer as well as between them and that in the middle. Nevertheless, the principle of force and opposing force (here: action and reaction) demands that the middle proton is exposed to counter forces, which together cause it to remain at rest.
On the other hand. For example, in a situation, a particle can only move perpendicular to a real force.
Solution: we assume two fictitious forces, which are perpendicular to each other. This is imposed on us in the situation. The choice is arbitrary, as is orthogonality. And not all can be real, for otherwise we would have overdetermination. In this situation, the resulting force is real, not the components.
Causal Relation/Solution/Bigelow/Pargetter: since sometimes the resulting force must be assumed as real, sometimes the components (depending on the physical situation) the causal relation should be explained as a relation of higher level between aggregates of forces.
Forces/quantum mechanics/Bigelow/Pargetter: in the quantum mechanics one does not use forces. For example, one does not say that a photon exerts a force on an electron.
Bigelow/Pargetter: however, we treat these cases as analogous because they appear to us to be similar enough. (See Heathcote 1989).
Field/Bigelow/Pargetter: also in the relation between field and particle, we allow ourselves to speak of forces and causation.
But we rather speak of interaction between two fields as between field and particle.
Quantum mechanics/Bigelow/Pargetter: "Interactions" are the legitimate heirs of the traditional "forces".
Field/VsBigelow/Bigelow/Pargetter: there are also cases where a field does not interact with a particle, but is nevertheless produced. This seems to contradict our theory. If a field is formed from a particle, one cannot speak of forces. An electric particle exerts no force on its own electric field. Nevertheless, it precisely causes this field.
BigelowVsVs: this is not a case of causation. The argument presupposes a separation of particle and field, which is not accepted by anybody. There is rather a unity. The field is part of the "essence" of the particle. This needs, however, to be examined in the light of further scientific development._____________Explanation of symbols: Roman numerals indicate the source, arabic numerals indicate the page number. The corresponding books are indicated on the right hand side. ((s)…): Comment by the sender of the contribution.
J. Bigelow, R. Pargetter
Science and Necessity Cambridge 1990