Berkeley’s Instrumentalism

One of the roles of philosophy is to clarify the concepts that are used in other subjects, as well as its own subject. Thus, when there is a breakthrough in, say, physics, there is usually a period of controversy as the new ideas sink in and are assimilated. Thus there were arguments over the ‘meaning’ of Newtonian mechanics, and similar discussions about the meaning of quantum mechanics.

Often philosophy follows quite carefully the ideas of the sciences. Philosophers, as I mentioned, usually see themselves as clearing away the intellectual clutter preventing or confusing ‘progress’. Not all philosophers, or physicists for that matter, follow the current scientific trends, however. A few are critical of new ideas, not because they are new, but because they do not make a lot of sense as originally put forward.

A case in point is George Berkeley (1685 – 1753). He is best known for an immaterialist philosophy (also known as ‘naïve idealism’), which no-one, I imagine, really believes today. However, he is interesting:

Virtually none of us are Berkeleian idealists but we love teaching Berkeley because he is a brilliant, mad Irishman who contrives wonderful arguments in support of (prima facie!) crazy conclusions. (Baber, H., The Trinity: A Philosophical Investigation (London: SCM, 2019), p. 5).

Berkeley, however, was also a critic of the new (for his day) Newtonian mechanics. In 1721 he published De Motu which, essentially (and as far as I understand it) has a go at the ideas of force, gravity, attraction, impetus and so on. It is important to understand that Berkeley was not guilty of the crime against progress which are often (wrongly) laid at the door of religious believers in general, that is dismissing something new because it is new, or because it does not fit with a particular set of religious doctrines. Berkeley’s objection is to these obscure ideas which seem to inhere in objects which are otherwise passive.

Berkeley does not dismiss Newtonian dynamics as false, of useless. He does not argue for a ‘better’ theory, one which removes these occult activities in bodies. What he does is question whether they are anything except useful calculational devices. That is, he has no objection to working out the trajectory of one billiard ball struck by another by means of resolving the forces on it onto a frame of reference and deducing the direction in which the second ball will move. What he does object to is the idea that these forces are in any sense real. They are calculation devices, to aid us in working out what is going to happen.

In this view, then, Berkeley is an instrumentalist. He views things like forces and attraction in gravity as a means of obtaining results, not as real objects in the world. He does have a point: try pointing to a force in the physical world. It always comes attached to a physical object and, if we did not simply accept that it existed, would be a weird concept which floated unattached in the world.

For Berkeley, a law of nature is a generalised principle, and explanation arises when phenomena follow the generalisations. Newton’s laws are therefore laws of nature because we can deduce from them regular phenomena which physical bodies experience – billiard balls bouncing off each other, for example. But the descriptive content of the laws are not, to Berkeley, important. What matters is the application of those laws, not how the results are calculated. We do not have to believe in forces, attractions, gravity and so on to use the laws and make predictions:

As for attraction, it is clear that this was employed by Newton, not as a true and physical quality, but only as a mathematical hypothesis. (De Motu section 17).

According to Berkeley, then, science aims at a sort of understanding of nature, a useful understanding, similar to that we obtain by studying the grammar of a language. Scientific laws are the grammar of phenomena, and we can use them to construct instances and cases in the real world. According to Berkeley, we go astray when we start to assign causes to physical objects. Causes, at least efficient causes, for Berkeley, should be assigned to incorporeal agents; in his case the agent is the Agent, God.

We do not have to buy into the whole or Berkeley’s metaphysics in order to get the point I am trying to make here. Nor is the point, in fact, about belief in God. Berkeley did believe in God – he became a bishop in the Church in Ireland – but that is not the point here. The point is that we do not have to believe that forces and so on are real, in the world, objects. They are, in Berkeley’s view, simply useful ideas to have around to calculate things with.

Whether you think that forces (etc.) are real or occult, however, is not something you can decide scientifically. Berkeley accepts the results of Newtonian dynamics, and, in fact, has no problems with the dynamics at all. He expresses scepticism about the existence of the concepts used to obtain the results but does not object to using the concepts to obtain the results. The results are the same whichever way you look at them. Newtonian realism or Berkeleian instrumentalism becomes a matter of choice, here. The calculations are the same, the mathematical derivations are the same and the experiments undertaken to verify the laws are the same.

I doubt there are many physicists or philosophers, or indeed anyone else, who would really doubt the existence of ‘real’ forces, but claims to experience forces do tend to drop away when you look at them in any detail. I may well feel the force of a wind, but that is because I am being bombarded by small particles at high velocity (and also pressure waves) and feel that. There is no ‘force of the wind’ per se. I feel a cumulative effect of it.

The fact is (and you might consider it a sad one, possibly, if you do not have a metaphysical bent) that when you drill down far enough, most scientific laws are grounded on a metaphysical choice, not on a set of hard facts. Some people would claim that the laws of physics are just brute facts about the universe, and they may be right. But such a claim is a metaphysical one, and cannot be proved from within science. Ultimately, the choice is a human one.

For more information (and with thanks to): Downing, L., 'Berkeley's Philosophy of Science', in Winkler, K. P. (ed.), The Cambridge Companion to Berkeley (Cambridge: CUP, 2005), 230-265.