Physical and Mental Substances: what are the stuffs of nature?

Here is a potted summary of a non-reductive 'propensity account' of physical and mental substances:

Quantum theory must deal with substance, but just not substance of the classical material or atomistic kind.  Rather, something that perseveres through time without existing in a actualized form at every moment. The substance would be something like the 'potentiality' or 'propensity' for acting, and that acting occurs with non-zero time steps, not continuously. This is the 'propensity interpretation' of quantum mechanics, initiated by Heisenberg and Popper. Because of the finite time steps, propensities exist and persist from one event to another actualization. Between events, therefore, they are the substances of quantum things.

We talk about mental information, and ask "what property of substance, makes it amenable to human cognition". You (like many others) are asking, 'what is the stuff of mind?'. My answer is an extrapolation of what I said above for quantum physics. It is 'potentiality' or 'propensity' but now of mental kinds. What is that, you ask? Do I know it? Yes: I say. It is the 'love' or 'desire' that make a person. For loves and desires are what in us persons that does persist. Again we make actualizing decisions intermittently. Between those decisions it is our love which persist. Love is our mental/personal substance. Just (certainly not!) material substance!

Quantum objects are propensity-substances in various forms. Those forms are the wave functions of quantum theory.
Mental objects are love-substances in various forms. Those forms are the information of mental kind, a.k.a thoughts and perceptions. The actions of love (a.k.a. decisions) have physical effects.

These ideas are based on the ideas of the kind Aristotle might have had without much effort, though in fact he did not. Just remember that there are two kinds of substances (at least), and the kinds are not reduced to another, or aggregates of other kinds. It is the job of physicists and psychologists to determine how the two kinds of substances actually cause things, and hence what they actually do.

There are functional correspondences between the way physical and mental things exist and operate, even though the substances involved are completely different and can never be transformed one into another.

Mental dispositions and desires

Psychology necessarily deals with dispositions and not just with what events actually occur. Even the behaviorists recognized that they should study tendencies to behavior and not merely the behavioral events themselves. Our question will concern the ontological status of these tendencies or dispositions.

Ryle (The Concept of Mind, 1949) takes the view that dispositional ascriptions “assert extra matters of fact” and claims that they are only “inference-tickets which license us to predict, retrodict, etc.” He quite explicitly denies that one should look for either causal or mechanistic explanations of the dispositions. This holds even in cases in physics and chemistry where there are explanations in terms of constituents and their propensities to attract and repel each other. His restriction against looking for explanations in terms of internal dynamics is, fortunately, largely disregarded in scientific practice.

We could interpret psychological dispositions in the same way that physics interprets potential energy. Bawden, for example, claimed in 1947 that “the role of the psychical in relation to the physical (in the living organism) is essentially the relation of the potential or incipient to kinetic or overt action.” I respond that potential energy is (again) a kind of disposition that must in some way exist, as a substance. 

In cognitive psychology it is a common starting point that mental activities consist of functions of information-processing modules, engaged, for example, in signal or symbol processing. This description refers only to the structural or formal aspects. Admittedly, structural changes are described, but no specific powers or dispositions for those processes are admitted. This is inadequate, however, from the point of view of any causal realism. Any account based on computation can only be realistic if it at least allows that the hardware implementations use objects with powers, as then physical symbol processing is consistently possible. Remember (from the previous post), that dispositions/causes remain absolute different in category from forms and information.

So, what is the actual nature of the dispositions that are operative in mental activities?  Are these just aggregations of physical dispositions, or are there ‘true mental dispositions’ that are distinct from the physical?  If the later were true, we would ask what impact the true human substances have on cognitive processing, since they will have their own characteristic powers and propensities not necessarily present in computers. The issue in psychology is thus whether the dispositions and powers that constitute the substance for mental objects and processing are related to the dispositions and powers manifest in the mind itself. I am thinking specifically of the emotional and motivational dispositions that make up the apparent life of mental feelings and intentions. These are powers that appear on first phenomenological analysis, so psychology should consider whether they could be the first ‘more fundamental’ underlying stuff of which cognitive and symbol processing is the activity.

According to Descartes, the soul (mind) is a substance and thought is the mode of its operation. This might explain what constitutes minds. However, Descartes does not offer a dynamical account to explain the operations of the soul. (On the contrary, he was pleased that the rational soul, as he conceived it, was completely outside the scope of the new empirical sciences and could be made subject to the edicts of ethics and religion.) In the end, Descartes never discusses reasons for the details of mental powers or capacities.  That is what we want really to discover!

Are propensities the Substance of things?

Are propensities (powers, etc.) the right kind of thing to be substance?  Let us examine the proposal from the previous post. 

One might object that propensities do not appear to have enough being, as they appear instead always to point to an incipient state of becoming. Are they, as Armstrong (1997) claims, always packing but never arriving?  Would objects made of such substance as proposed here actually exist, or only potentially exist, or (perhaps) exist potentially?  Bird (2007) responds to this by pointing out that this objection assumes that powers or dispositions are not fully actual. Rather, he says, we should insist that powers are actual full-blooded features of objects and that what is merely potential are their manifestations. I would respond slightly differently: powers are the actual full-blooded substance of objects and are not merely the ‘features’ or ‘properties’ of objects.

Perhaps we wonder whether objects made of such substance are really ‘full-blooded’. Do such substantial objects persist as objects should?  How do they have being?  Can they be individuated properly?  Are they simple units, or can they be divided?  Could elementary particles be of such substances?  Could we be such objects and still feel our own reality?  Let us discuss some of these issues.

Do these new kinds of substance persist?  There is certainly no need for them to persist forever, but can they persist through accidental changes while maintaining their essential nature?  To answer the question about persistence, we note that dispositions are possessed even when they are not being manifested. A vase is still fragile when it is not breaking. The fragility persists for a finite duration: at least from one contact event until the next. What I am asserting is that the corresponding substance of the glass persists for at least exactly that same duration. In that duration, it may change its position, orientation or illumination. These are the variable accidental properties that vary while the underlying substance (fragility and the other dispositions) remain the same. Whether the underlying substance persists forever is the same question as whether the fragility (etc.) persists forever. That can be answered by looking at the future adventures of the vase in the world.[1] If the fragile glass ceases to exist, then the substance ends, perhaps by being changed into another kind of substance. That substantial objects might persist only for a finite time does not render them any less enduring or persistent objects during that time.

How do these substances have ‘being’?  The recent dispositional essentialists have taken all properties as ‘powers, and nothing but powers’, so we wonder if we can take all objects similarly. The claim was thought by Bird (2009) to include all properties, including all those previously thought categorical such as position, shape and structure. I do not hold such a strong view. Particular objects have both dispositional and categorical properties, once we understand how this is to be conceived. The dispositional properties are instantiated by the underlying dispositional substance, whereas the categorical properties are instantiated by the form or structure of that substance which makes up this specific object. In this way we have what Martin (1993) calls a ‘Janus-faced’ or ‘dual-aspect’ view, but of objects rather than of properties. We are thereby constructing a notion of substance wherein substantial objects legitimately have both dispositional and categorical aspects. We do not follow Jacobs (2011) in having ‘powerful qualities’ that have both dispositional and qualitative sides. Rather it is the substantial objects that have both. Now, some but not all properties are dispositional. We do not deny the semantic distinction between dispositional and categorical properties but rather reinforce it. Neither do we have a ‘neutral monism’ whereby the dispositional and categorical are ‘modes of presentation’, following Mumford (1998), of the same instantiated properties.

Many philosophers since Prior et al. (1982), and recently, Rives (2005) have argued that dispositions are ‘causally impotent’ following the argument that “if dispositions are distinct from their categorical bases, and their bases are efficacious, then the dispositions themselves are impotent.” Rives explicitly assumes that “the causal efficacy of categorical properties is not in question”. I disagree. I think categorical properties such as size, shape, structure are by themselves never causally efficacious. We saw that above. Such properties are only efficacious when they are shapes or structures of some substantial object, and this requires the participation of dispositional properties. A ‘base’ can never be a structure per se and hence never purely categorical.[2]

A summary of the new position is to say that specific objects are unions of form and power, of qualitative and dispositional aspects.[3] Objects are structures of propensity, namely forms of substance, in a good Aristotelian manner. Forms may be examined in great detail by form-al sciences such as mathematics and logic, but no natural changes can be generated by formal constructions. For example, contemporary attempts in physics to construct ‘it from bit’ (to derive existence from form) can only produce a static (timeless) universe without changes or causes of change. I would instead say that forms are the means by which dispositional powers operate, since the power-substances can only operate if they are arranged in some form or structure that allows for interaction and movement. Conversely, forms can only have an impact on the world if they are the forms of some propensity, as thereby a physical object in the world is in existence and has powers to influence others. This is why I said that objects in the world are required to be unions of form and power: they require powers to be in some form and require forms to be of some power. The resulting union has an existence that goes beyond either ingredient by itself.[4] In a natural object, the power and form are actually inseparable and only abstractly distinguishable. We can (and should) intellectually distinguish them—as recent philosophers have emphasized—but that does that mean that they can ever exist apart.

Can these substantial objects be individuated?  Can we identify individual objects made of such substance?  It certainly does not seem that we can divide powers or propensities themselves into parcels, with some for each individual object in the world. I can only see individuation proceeding via the specific forms or trope that the substance-stuff has in specific objects. That is, identifying individual objects, as forms of the underlying substance-stuff, can only proceed by identifying those particular forms used in each individual object. We may say that even the individual and specific existence of an object depends on the specific forms that inform the essential underlying powers/propensities of the substance.

Some scientists may be suspicious of the idea that there is a fundamental level where objects are composed of dispositions directly and do not have parts in substructures. Would that not be the end of science?  No, because science’s task is to first determine which is the fundamental level. Secondly, scientists try to exactly characterize and understand all those dispositions, both common and uncommon, in order to predict their exact operation. Any such claims are subject to empirical verification or revision.

Finally, we must consider the logical plausibility of this proposed identity. Grammatically, nouns in sentences are the agents of actions and refer to the bearer of causal influences. The object of an action must cooperate in the operation of those influences.[5] This is entirely consistent with the present claim that subjects and objects are themselves forms of propensity. It is the nature of powers and propensities to be causal influences, so any thing constructed from them will be the bearer of causal influences. We must agree, therefore, to a grammatical move of powers from being adjectives within predicates to being the substance of subjects and objects. Then we must envisage as nouns the forms of such powers and propensities. This seems to me to be quite feasible.

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[1] I would doubt that vases are eternal. I not believe that electrons or nuclei are necessarily eternal either.

[2]  Psillos (2006) also makes this mistake, when he argues that “fundamental properties [..] flow from some fundamental symmetries," for symmetries, as purely mathematical structures, can never physically ‘flow’, and can never produce physical objects. Rather, in our Aristotelian framework, they describe the properties of objects and, here, relations between those properties. It cannot be that “elementary particles are the irreducible representations (irreps) of a group," again because groups (or even their representations) have no causal powers.

[3]  Neither can exist by itself. No dispositions can exist except in a form, and no forms can exist except as forms of dispositions.

[4]  Ellis (2010) has recently written in support of this view of forms as being both categorical and necessary for the operation of powers.

[5] A hammer and a vase must have powers to interact with each other if fragility is to be manifested this way.

References

Armstrong, D. M. 1997. A world of states of affairs. Cambridge; New York: Cambridge University Press.

Bird, Alexander. 2007. Nature’s metaphysics: Laws and properties. Oxford; New York: Clarendon Press; Oxford University Press.

Bird, Alexander. 2009. Structural properties revisited. Oxford; New York: Oxford University Press: Clarendon Press;.

Ellis, Brian D. 2010. Causal powers and categorical properties. New York: Routledge.

Jacobs, J.D. 2011. Powerful qualities, not pure powers. Monist, 94(1), 81–102.

Martin, C. 1993. The need for ontology - some choices. Philosophy, 68(266), 505–522.

Mumford, Stephen. 1998. Dispositions. Oxford; New York: Oxford University Press.

Prior, E.W., Pargetter, R., and Jackson, F. 1982. 3 theses about dispositions. American Philosophical Quarterly, 19(3), 251–257.

Psillos, Stathis. 2006. What do powers do when they are not manifested?  Philosophy and Phenomenological Research, 72(1), 137–156

Rives, B. 2005. Why dispositions are (still) distinct from their bases and causally impotent. American Philosophical Quarterly, 42(1), 19–31.