Philosophy
Lolll
LECTUREThemechanicalworldpicture.docx5
LECTURE: The mechanical world picture
Having looked in some detail at Aristotle’s and Aquinas’s version of dualism, we are (after our first exam) going to turn to Descartes’ version, and then to materialism. But to set the stage for our look at both of these views, we need first to say something about the understanding of the natural world that came to dominate Western thought in the early modern period, at the time of the Scientific Revolution.
It was called the “mechanical philosophy” or, as Tim Crane calls it in the reading from chapter 1 of The Mechanical Mind, the “mechanical world picture.” And it pushed to the side – to the status of minority opinion – the Aristotelian view of nature which had previously been dominant, and which we’ve been discussing for several weeks.
Abandoning Aristotle
Aristotle and his medieval admirers (like Aquinas) tended to see all of the natural world on the model of living things. That doesn’t mean that they thought that the whole world is alive. They did not think that. But it was in living things that one could most clearly see all four of Aristotle’s Four Causes. In particular, it was in living things that one could most clearly see final cause or purpose (in the functions of biological organs), and formal cause (in the sharp differences between the substantial forms of different kinds of living thing).
Now, early modern scientists – beginning in the 17th century, as the Aristotelian tradition associated with Aquinas began to decline – came to emphasize the idea that what is important for purposes of physics is what can be quantified, what can be put in the language of mathematics. For these are the aspects of nature which can be precisely measured and predicted, and which can be thereby exploited for technological purposes. And the prediction and technological control of nature came to be seen by founders of modern science like Francis Bacon and Descartes to be a central purpose of science. (This is the meaning of the remark famously attributed to Bacon to the effect that knowledge is power – it is power over the natural world, specifically.)
The language of the new science
Hence mathematics would become the language in which, it was thought, a respectable theory in physics ought to be formulated. Any part of nature that could not be described in such terms could, on this view, be ignored for purposes of physics. (Let the philosophers deal with it!)
But here’s the thing. Aristotelian formal and final causes are not quantifiable, not the sort of thing that can be captured in mathematical terms. Neither are other Aristotelian concepts, such as actuality and potentiality. Qualitative features of nature like color, sound, taste, heat, cold, etc. are also not quantifiable, or at least not entirely so. Moreover, they vary from perceiver to perceiver. Colorblind people don’t see colors the way people who aren’t colorblind do, a bucket of water will seem warm to a person whose hand has been soaking in cold water but cool to someone who had been soaking it in hot water, and so on. (Recall examples of this sort we discussed earlier in the semester.)
The new picture of the natural world developed by the founders of modern science thus put aside notions like formal and final cause, actuality and potentiality, and “secondary qualities” (as features like color, sound, taste, heat, etc. came to be called). And while it preserved the idea of material cause, it re-defined it. Matter was no longer to be understood as the potentiality to take on form (since concepts like potentiality and formal cause had been thrown out). Instead, matter was characterized entirely in terms of “primary qualities” like size, shape, motion through space, etc., which could be given an entirely mathematical or quantifiable description.
What color is the dress really? None of them! It’s only a secondary quality
Efficient cause too was kept but re-defined. Recall that for the Aristotelian, an efficient cause aims or points to its typical effect, where the generation of the effect is the final cause or goal of the efficient cause. Obviously, if you throw out final cause, you can’t think of efficient causes in this way. So instead, to say that A is the efficient cause of B was re-interpreted as the idea that there is a mathematical law linking A and B. It is to say that things of type A tend as a matter of fact to be followed by things of type B, in a way that the laws of physics describe. (But why do these laws of physics operate? Some, like Descartes and Newton, attributed this to God. Others did not. Either way, the question was treated as one that physics needn’t answer. Again, let the philosophers deal with it!)
So, the physical world, on this new view, can be understood as nothing more than colorless, soundless, odorless, tasteless particles moving purposelessly through space in patterns describable in terms of mathematical laws. That’s it! No reference to formal and final causes, actuality and potentiality, or secondary qualities is needed – again, at least not for purposes of physics.
The world as machine
This led to a new conception of nature, where machines, rather than living things, were the model for everything else. Think of a watch (a popular example in those days). At one level of description, it’s just a collection of metal bits – gears, springs, screws, etc. – arranged in a certain way. Of course, it also has a final cause, i.e. to tell time. But that purpose is not really there in the watch itself. It’s in us, in the purposes that we have in making and using the watch. If you want to understand the behavior of the watch itself, you can just focus on the nature of the metal bits and how they are put together. That will allow you to predict and understand the behavior it exhibits as the hour and minute hands move across the face of the watch, etc.
“Welcome to the Machine.” (Old Pink Floyd song.)
All physical objects, according to this new model of nature, can be understood this way. They can be explained as nothing more than collections of smaller parts – ultimately, collections of particles – arranged in a certain way. And they can be explained without reference to final causes or purposes. It’s just dumb bits of matter pushing against one another according to physical laws, without any goal or purposes.
One implication of this is that everything in the physical world – tables, chairs, rocks, trees, dogs, cats, human bodies, and so on – is really just the same kind of thing, namely particles in motion. There are, on this view, no sharp differences in kind between things (as the Aristotelian doctrine of substantial form claims) but only differences in degree of complexity.
Another implication is that the Aristotelian distinction between “nature” and “art,” between what is natural and what is artificial, breaks down. For Aristotle, a truly natural object has a substantial form (not an accidental form) and built-in or intrinsic final cause or purpose (not extrinsic or externally imposed purpose). For example, a tree has, because of its substantial form, a built-in tendency to aim toward goals like sinking roots, carrying out photosynthesis, etc. That’s what makes it a natural substance. By contrast, the bits of metal that make up a watch have, again, no built-in tendency to tell time. That tendency only results from people putting that purpose into them from outside, by imposing on the bits of metal a certain accidental form. That’s what makes a watch an artificial kind of thing, an artifact.
But for the new, anti-Aristotelian mechanical model of nature, there are no substantial forms, and there are no built-in final causes or purposes. Rocks, trees, dogs, and other natural objects are now seen on the model of “art” – as artifacts, like the things we make (tables, chairs, watches, etc.). As collections of bits of matter with, at most, externally-imposed purposes.
The natural world is like a machine, then. Who made the machine? For thinkers like Galileo, Newton, Descartes, et al., the answer is that God made it. They basically took the Aristotelian-Thomistic idea of God as Unmoved Mover (or “purely actual actualizer”) of the world and replaced it with the idea of God as machinist. (This is where the idea of God as a kind of “watchmaker” or inventor comes from. That isn’t the sort of model for God that an Aristotle or Aquinas would have used.)
Of course, some later thinkers delete God from the picture. But the point for the moment is that the world-as-machine model came to replace the Aristotelian model of explanation in terms of the Four Causes, actuality and potentiality, etc.
The world as clockwork
Problems with the mechanical philosophy
That the natural world came to be modeled on a machine is the reason this view came to be called the “mechanical philosophy” or the “mechanical world picture.” And, as I say, from the 17th century onward it became the dominant model, and pushed the Aristotelian view to the margins.
Here’s the problem, though. Almost immediately, it became evident that not everything can be explained in terms of the mechanical philosophy, however we spell out its details. For one thing, it is hard to see how you can explain thought and consciousness in terms of nothing more than particles in motion. A few early defenders of the mechanical philosophy (like Thomas Hobbes) thought you could, but others (like Descartes, Leibniz, and Locke) thought you could not. That’s one reason they located thought and consciousness outside the physical world (in Descartes’s case, in a non-physical soul). We’ll come back to this later.
For another thing, properties like gravity were not explainable in mechanical terms. Gravity operates at a distance rather than by way of physical contact between particles. As time went on, it became clear that a model of particles pushing and pulling against one another simply wasn’t going to work even for all physical phenomena.
Still, and to repeat, the mechanical philosophy nevertheless pushed the Aristotelian way of thinking about nature to the sidelines, where it remained as a minority view rather than the dominant view it had once been. And the general spirit of the mechanical world picture has remained dominant to this day, even if some of the details have fallen by the wayside. But note that this was not really a scientific difference of opinion. It was a philosophical difference of opinion about how to interpret science and scientific method.
Introduction to the Scientific Revolution:
https://www.youtube.com/watch?v=rQ2dSTQwJo8
Noam Chomsky on the Mechanical Philosophy:
