Examples.
~ Descartes also wants to explain all terrestrial phenomena (e.g. weight) in mechanical terms, as well as all celestial phenomena: Aristotle's 'moving minds' and Kepler's 'moving soul' in the Sun are both thrown out, replaced by vorteces. Any other (possilby occult) quality that cannot be understood purely mechanically is thrown out too. In Principles of Philosophy sec.186, Descartes writes: "I have described... the whole visible universe as if were a machine: I have only considered the various shapes and movements of its parts." And in sec.203, he says that the only difference between man-made and natural machines is size: nature is composed of 'micro-machines.'
~ Descartes, in Treatise on Man, aims to understand the human body as a machine.
~ Hobbes echoes this idea in the introduction to Leviathan: he first says that any self-moving machine, such as a watch, has a kind of "articifical life." For we humans are machines: "For what is the heart, but a spring; and the nerves, but so many strings; and the joints, but so many wheels?"
~ Hobbes takes this further: not only can the human body and its operations be understood mechanically, but so can all of human society. A state or commonwealth is an "artificial man." The state is the primary focus of Leviathan (though we do not read those parts of the book). But this idea that the state is artificial was a radical one: human society was previously thought to be natural, not man-made -- and more similar to an organism than a machine.
The clock metaphor. Several Early Modern thinkers agreed with Robert Boyle's claim that the natural world "is, as it were, a great piece of clock-work." [Look at the frontispiece to the Boyle readings: the Strasbourg Cathedral Clock.] What features are clocks and natural occurrences supposed to have in common?
(1) As we have said, nature is a machine, and can be fully understood using purely mechanical terms, just like a clock. We do not think of nature or its parts as organisms.
(2) A clock's behavior is very regular -- just like the movements of the celestial bodies, and just like many other natural phenomena.
(3) In many cases, the wheels and gears of a clock, which explain the hands' movements that we see, are hidden from view. In just the same way, natural mechanisms are hidden from direct human observation, usually because they are too small to be seen. (Think of Descartes' 'micro-machines.') But they are nonetheless responsible for what we can see.
(4) Clocks and other machines can appear to be alive, have souls, or act purposively -- but we know that they are not, and we can explain their apparent purposiveness just by the levers, gears, and pulleys that make up the machine. For example, in the picture of the Strasbourg clock, there is a rooster in the upper-left part of the clock. This rooster would crow three times at noon every day, rocking its body back and forth. It appears to be alive and acting with a purpose in mind, but we know that it is not -- simply because we know it is a machine. So if that can be explained without appeal to souls or purposive/ intentional action, perhaps many other things in nature can be explained without appeal to souls or purposes. And this is one of the ideas common to many of the thinkers we call 'Early Modern': they tend to reject explanations of physical phenomena that appeal to purposes (Aristotle's "final causes") or souls or intelligences.
Characterization of matter. For Boyle, the only (mechanical) characteristics of matter are:
for individual bits of matter
- size ("bigness")
- shape
- orientation ("posture")
for collections of bits of matter
- order (e.g., which bits are at the top vs. which bits are at the bottom)
- texture
Lsstly, Boyle (like Descartes and Hobbes) considers all matter to be "altogether unactive" (p.141); in other words, matter is completely passive and inert. (This will contrast with the Paracelcian chemists.)
Characterization of motion.
- A body in motion can (i) break up bodies, and (ii) impart its motion to other bodies.
- There are no (Aristotelian) 'natural places': that is, certain types of matter all by themselves do not strive or tend to go up or go down.
Further aspects of Boyle's mechanical philosophy.
~ By calling his view 'corpuscularian,' Boyle intentionally avoids the questions about the existence of atoms (indivisible bodies) and the void (though Boyle himself believed in it).
~ He also includes claims about the beginning of the universe. At the time of creation, God
(i) arranged matter into (more or less) its present form of animals, plants, etc. (He thought Genesis should be interpreted literally);
(ii) imparted motion to matter;
(iii) established "rules of motion" ("laws of nature")
After the universe is created, "the phenomena of the world... are physically produced by the mechanical affections of the parts of matter... according to mechanical laws" (139). That is, after God sets up the matter and lays down the laws of motion, God does not need to intervene to produce any non-miraculous physical events.
1. The "intelligibleness or clearness of Mechanical principles and explications" (139). Boyle thinks this is a great advantage over Aristotelian notions like matter and form, and Paracelsian/ Chemical notions such as astral influences. It is not entirely clear what is meant by these terms, and people can disagree about what exactly they mean. Boyle thinks this contrasts sharply with the notions of shape, size, and motion -- everyone can agree what such terms mean, and fully understand other people's claims about the shape, size and motion of a particular thing. Furthermore, when an Aristotelian or a Paracelsian finds a purely mechanical explanation, they usually prefer the mechanical explanation: for example, Aristotelians do not invoke their planet-moving 'motor intelligences' when they explain the solar eclipse: it is just the moon coming between the earth and the Sun.
Its principles are fundamental, chronologically and conceptually.
(i) Chronologically: the universe as we know it could not begin without both matter and motion.
(ii) Conceptually: neither the concept of matter nor that of motion can be reduced to any simpler concepts (or to each other).
Its principles are "comprehesive" or universal.
- The number of different shapes, sizes, and motions are all virtually infinite -- and so is the number of combinations of smaller parts. Because of these many possibilities, it appears that mechanical accounts can be given of basically everything. Boyle gives an alphabet analogy, to convince his opponents who think mechanical explanations can only be given of a few types of phenomena. With just 26 letters, infinitely many books can be written, on any topic, and in several languages.
- Additionally, Boyle points out that the same mechanical causes produce the same mechanical effects on very different scales of size: the basic design and operation of a wristwatch is the same as a huge town clock -- the hands and gears are just bigger in one. Therefore, Boyle concludes, the mechanical principles hold good for very large things, very small things, and everything in between.
Comparing the Mechanical Philosophy to its rivals. Boyle's basic claim is that any apparent competitor to the mechanical philosophy is either unintelligible, not fully informative, or else compatible with the principles of natural philosophy.
- Platonists. For example, the Platonic soul of the world or anima mundi, which we saw in the Timaeus and in the Neoplatonists, might be compatible with the mechanical philosophy: Boyle points out that it sounds very similar to Descartes' "subtle matter," which pervades the stars and heavens. But if the soul of the world (or angels, or seminal reasons, or whatever) act in non-physical, non-mechanical ways, then, Boyle says, it is impossible to understand how they cause any change in the world. As he puts it: if an angel supposedly causes a change without changing the arrangement or movement of matter, then how is there any change at all?
- Chemists/ Paracelsians. A typical chemical explanation that a Paracelsian might give is: 'This material burns easily because it has a great deal of the sulphuric principle in it.' Boyle says these explanations "are not the most fundamental and satisfactory: for the chemical ingredient itself, whether sulphur or another, must owe its nature and other qualities to the union of insensible particles in a convenient size, shape, motion or rest" (147). That is, we still want an explanation of why sulphur is flammable. Furthermore, material alone is never a sufficient explanation: knowing that a watch is made of a certain amount of metal and glass does not explain how it keeps time.
Mechanical Principles as a decoder key. How does this relate to other conceptions of science we have seen already?
Ch.1: Sensation.
- All of our ideas ultimately come from our sensory experiences. (What about unicorns and dragons? We take parts of our sensory experiences and put them together, even though we've never seen them together.
- All our ideas are 'internal' to us -- so why do we think that we are perceiving objects external to ourselves? When something external presses INward on our sense organs, our organs resist, creating a counter-pressure, which is directed OUTward. Because this counter-force is outwardly directed, we think the we are perceiving something external to ourselves.
- Hobbes makes a claim we have seen before, in Descartes as well as the ancient atomists: "All the qualities called sensible are, in the object which causeth them, but so many motions of the matter." This is fairly close to our current scientific conception as well: we don't think of colors, tastes, sounds, etc. as somehow IN objects themselves. But what is Hobbes' reason for this view? Basically, that these sensory qualities can be found separated and distinct from bodies: we can see colors, hear sounds, etc. in dreams; we hear sounds in echoes and see colors in mirrors; if you press on your eyes you will see light, and if you are hit in the ear you will hear bells. The fact that we can experience these qualities independently of the objects gives us reason to think the qualities are in US, instead of in the external things.
Ch.2: Memory/ Imagination
- Hobbes attacks the idea that we should ascribe 'appetites' or inclinations to physical objects, such as an inclination to reach its natural place, or to come to rest. This echoes the Early Modern rejection of purposes in explaining physical phenomena, and its conception of matter as passive.
- Hobbes accepts the Cartesian 'law of inertia' (a body will maintain its current velocity unless another body strikes it) -- and applies it to human thoughts. The reason we can remember things (and imagine them) is that some traces of the motions the thing originally induced in our body are still around.
- So why are we not always thinking of everything we've ever experiences, since all the motions are bouncing around in us now? Because the motions created in us by the objects we are currently perceiving overwhelm and outweigh all the residual motions of our old perceptions
- This account of memory/ imagination explains why we dream -- and why our dreams are of things we've experienced, but still very strange: all these old motions are bouncing around in us, without a current perception to overwhelm them.
Ch.4: Language
- Hobbes makes the apparently reasonable demand that we know exactly what our words mean -- if we don't, we'll get confused and lost. So, Hobbes says, we should start any inquiry with definitions, which aim to settle what our words mean. Hobbes goes so far as to say that geometry is the only true science, for it alone begins from definitions. Several other Early Moderns took geometry as their paradigm and model for their different studies.
- If we begin from proper definitions, Hobbes says, we will recognize that phrases such as 'incorporeal substance' are meaningless -- for part of the proper definition of 'substance' is that it have some body or extension. So Descartes' notion of 'thinking substance' is not rejected on empirical grounds, but rather because he has not paid sufficient attention to language.