On Physics and Other Natural Phenomena

In the opening lines of the second chapter of his novel Leviathan, Hobbes states:

That when a thing lies still, unless somewhat else stir it, it will lie still for ever, is a truth that no man doubts of.  But when a thing is in motion, it will internally be in motion, unless someone else stay it…(7). 

Those of you that are familiar with classical mechanics will notice that what Hobbes describes here is Newton’s First Law of Motion.  If you have yet to encounter Newton’s Laws of Motion (or if you have forgotten what they were), I will quickly recap them here.

There are three fundamental laws of motion, each which describe the motion of an object (or a collective group of objects) when a outside force is applied to it.  These laws are as follows:

  • Newton’s First Law (aka The Law of Inertia): An object will move uniformly (will move with constant speed and direction) unless acted upon by an outside net force.  Eg. A ball that is thrown horizontally will continue to move horizontally–at the same speed and in the same direction as it was thrown– forever unless some outside force (such as gravity or air resistance) acts upon it.
  • Newton’s Second Law: The force (F) on a object is equal to the mass (m) of the object multiplied by its acceleration (a)


Basically, this law states, that if an object does not have a mass (or if the object is not accelerating), then a force cannot be acting on it.

  • Newton’s Third Law: For every action there is an equal and opposite reaction (“Equal and opposite” is short for “equal in magnitude and opposite in direction”).  E.g. When you hit a ball with a racket, the force that the racket exerts on the ball is equal in magnitude and opposite in direction to the force that the ball applies on the racket.  You can observe this effects of this law by pushing on a table with your hand.  You will notice that even though you are pushing on the table, the skin on your hand will be indented where it is touching the table.  This happens because the table is exerting a force back on you!

Returning to Hobbes, one might begin to see how these laws could pertain to Hobbes and his argument.  After all, as Dr. Hendricks pointed out in the lecture and in seminar, to Hobbes:

life is but a motion of limbs,….For what is the heart but a spring; and the nerves, but so many strings; and the joints, but so many wheels, giving motion to the whole body… (3)

Humans are nothing more than automata to Hobbes, “engines that move themselves by springs and wheels” (3), things that act in a predictable and perpetual manner in accordance to Newton’s First Law of Motion.

Yet, Newton’s Second Law is also equally applicable to Hobbes’ argument.  In chapter I, Hobbes states that humans are able to perceive things when they sense them.  Sense, as defined by Hobbes, is the “diversity of appearances” (6) that are produced when an object acts on a person’s body.  He then goes on to say that:

The cause of sense is the external body, or object, which presseth the organ proper to each sense,…which pressure, by the mediation of nerves and other strings and membranes of the body, continued inwards to the brain and heart, causeth there a resistance, or counter-pressure, or endeavour of the heart to deliver itself… (6)

If we refer back to Newton’s Laws of Motion, we see that what Hobbes has described here sounds awfully similar to the Second Law of Motion.  For, in the quote above, there is an external body, or mass, applying a force on another mass (the human body), causing the mass on which this force is applied to accelerate (move).  But, because this force that allows objects to be sensed can only be applied by a mass on another mass, only things with masses can perceive and be perceived.  Furthermore, Hobbes comes to conclude that names such as “incorporeal body” and “incorporeal substance” are “contradictory and inconsistent” (21).  By this reasoning, if one is to accept that God or the soul exists, then they both must be corporeal and have a mass.  However, this means that the Law of Conservation of Mass would then apply to both God and the soul.  The Law of Conservation of Mass states that: mass cannot be created nor destroyed; it can only be rearranged into different forms.  If this is the case, then what happens to your soul when you die? Also, if the human population is continuously growing and matter cannot be created, then how are new people being born?

In seminar, Dr. Hendricks (and I apologize in advance if I get this wrong) said that, later in Leviathan, Hobbes proposes that, immediately after death, nothing happens.  But, eventually, your soul is resurrected in a new body somewhere on Earth.  However, the chapter in which Hobbes argues for this is not within the prescribed reading for Arts One.  Another person in my seminar also said that it could be likely that (and I am sorry if I get this wrong, too) your soul might go to another materialistic place when you die.  As the matter of the soul is not being created nor destroyed in either case, the Law of Conservation of Mass is upheld.  Thus, both of these propositions could occur if the soul was corporeal.

However, I don’t feel like my second question was adequately answered in seminar.  Since we are doing two weeks of Hobbes, I hope that we can reflect on this question and, perhaps, come up an answer for it.  Please feel free to leave a comment even if you aren’t in the Hendricks seminar!

Okay, this is a bit of an aside to what I was talking about previously, but I am going to mention it anyways.  In Chapters XIV and VX, Hobbes prescribes a set of laws, which he refers to as the Laws of Nature.  But, why does Hobbes choose to give these laws this name? After all, when I hear the word “nature”, I think of the way things  are in their natural state.  According to Hobbes, the natural condition of mankind is “a war…of every man against every man” (76).  But, in Chapter XV, Hobbes states that some of his laws of nature “only concern the doctrine of civil society” (99) and, thus, would not apply in the natural state of man, which is confusing.  In seminar, Dr. Hendricks pointed out that Hobbes defines a Law of Nature as a:

precept or general rule, found out by reason, by which a man is forbidden to do that which is destructive of his life or taketh away the means of preserving the same, and to omit that by which he thinketh it may best be preserved” (79)

By definition, Hobbes’ Laws of Nature describe the natural order of the world.  Hence, the Laws of Nature are not like a civil law, which are prescribed by the commonwealth, but are more akin to fundamental laws, such as Newton’s Law of Motion, which describe the way that the world works.  Newton’s Laws of Motion describe what is required for things to move.  Likewise, Hobbes’ Laws of Nature state what needs to occur in order for well functioning groups of people to exist.  Yet, Dr. Hendricks also made it clear that, because people have various different opinions  on what Hobbes means when he refers to the Laws of Nature, there is a lot of scholarship on this matter.  If you think there is another reason why Hobbes calls his laws the Laws of Nature, please consider leaving a comment as well.  I’d love to hear what you have to say about this!

3 thoughts on “On Physics and Other Natural Phenomena”

  1. Hey Cara,

    I really appreciate the amount of thought and care with which you approach the text and synthesize your knowledge of the natural sciences. Since Hobbes describes in Ch. IX “the several subjects of knowledge”, and the study of human behaviour and the laws of nature is one of them, we assume that his logic ought to hold all the way through to his arguments regarding the soul as well. However, this point about the corporeal soul is one that I don’t think Hobbes refutes adequately, or, at least, the need for technical and biblical knowledge to support one’s arguments one way or the other about heaven or about the conservation of the mass of the soul makes it difficult for us to discuss adequately in seminar.

    This connection you draw between the interaction of matter and senses and the Laws of Motion is very interesting – it begins to quantify the metaphysical things as having mass (not necessarily in a physical sense, but they need to have “mass” in the metaphysical plane in order for the Law to stand). However, when applying the Second Law to life and death, I feel we need to cleanly separate the biological and the spiritual sense – physical mass and existence of the nutrients, elements, etc. as opposed to the renewal and continued existence of a soul. For your point about people being born, the theory should hold biologically, as nutrients and amounts of the natural elements needed for life are transferred via consumption of food, the sun, etc. (I can’t get technical about this). Even in a person’s death, the physical nutrients contained in that person’s body don’t just magically disappear, but go somewhere, whether they decay into the soil or become other forms of matter. But as to new souls being generated, how might we try to explain that under Hobbes’ theory of the corporeal soul? How do we explain where a mind comes from, from whence it derives its uniqueness, and what happens to it when its physical body expires?

    – Elliott

    1. Hi Elliot,

      Hmmm…you do have a valid point; I can see why we might need to separate the physical mass of the human body from the mass of the soul. After all, a rock has a physical mass, but that doesn’t necessarily mean that it has a soul. So, if we are to assume that the mass of the soul is different from the physical mass of, say, your body, then do we assume that, like all other forms of mass, it can freely change from one form of mass to another? For instance, energy is another conserved quality in physics. All forms of energy, from light energy to rest energy have a mass. The two most basic forms of energy are kinetic energy, which is the energy of motion, and potential energy, which is energy gained due to an object’s position in space. If we stretch a rubber band, then it will have a lot of potential energy due to its stretched position. But, the instant we let go of the band, it snaps back to its original position and (nearly) all the potential energy is has is converted to kinetic energy (motion). Thus, energy is neither created nor destroyed.

      Likewise, if we assume that the soul can change from one form of soul to another, then the “soul mass” will be conserved. Thus, the soul of a dog could become the soul of a human, and vice versa. If this is the case, this could be a possible explanation to the whole “where do the souls of newborns come from” question. After all, there are living things on Earth that are so small that we can’t even see them. Thus, when they die, their souls could be resurrected in a human body. However, I don’t really know how Hobbes would feel about this proposition. After all, in Chapter III of “Leviathan”, Hobbes states that all living creatures, other than man, “has no other passion but sensual, such as are hunger, thirst, lust, and anger” (13). Hence, only man can reason. Yet, do not understand why the soul of a dog should suddenly gain the ability to reason just because it was resurrected into the body of a human. I mean, if the soul of the dog can gain the ability to reason by being in a human body, then what was stopping it from having the ability to use reason before?

      Oh wait, never mind. In Chapter V, Hobbes states: “it appears that reason is not…born with us, nor gotten by experience only…but is attained by industry, first in apt imposing of names, and secondly by getting a good and orderly method in proceeding from the elements” (25). As stated in this excerpt, reason is not something humans are born with. In fact, its our ability to use words to give things universal names that enables us to reason. Therefore, because a dog cannot speak to another dog, the dogs cannot create universal names and, thus, cannot reason. But, if the dog’s soul was transferred to a human body, then the soul would be able to use words to communicate with other humans and, therefore, gain the ability to reason.

      However, the Law of Conservation of Mass states that mass itself is conserved, not that a particular type of mass is conserved. Thus, there is no guarantee that “soul mass” will become another soul. In fact, because rocks have mass, by the Law of Conservation of Mass, your soul could become a rock. But, honestly, I don’t know what Hobbes thinks about this. Maybe he thinks soul mass can only change into soul mass. But, based on what I have read, I cannot say what Hobbes’ opinion might be on is on this particular matter.

      As for your question about where the mind comes from, I will assume that you are referring to “thought” rather than to the physical entity of the brain. According to Hobbes, the “train of regulated thoughts is of two kinds: one, when of an effect imagined, we seek the causes, or means to that produce it; and this is common to man and beast. The other is when, imagining anything whatsoever, we shall seek all possible effects that can by it be produced; that is to say, we imagine what we can do with it when we have it. Of which I have not at any time seen any sign, but in man only…” (13). So, thought seems to be reliant, to some extent, on the body that your soul is in. Furthermore, in Chapter I, Hobbes defines a single thought as a “representation or appearance, of some quality or other accident of a body without us, which is commonly called an object” (6). Thus, to have a thought one must first “sense” an object. As I mentioned in the original post, Hobbes believes sense arises when an outside mass puts a force on some part of your body. However, your body’s shape determines how an object is able to push on your body. Therefore, the uniqueness of thought seems to arise from the shape of your body and the manner in which it is pressed by other objects. However, because your soul can be resurrected into a new body when you die, I suppose the way that you think will change with your body. After all, your new body will not have exactly the same shape as your old body did. Thus, objects will be pushing on your new body in a different way and you will have different thoughts. I don’t know what would happen if your soul wasn’t resurrected into a new body after you died. I probably could look into it, but this comment is waaaayyyy too long already, so I will just stop here.

  2. Okay, this is a really interesting discussion! I’m not sure I can add much to what’s already been said, but here are some things I found while going back to the text.

    1. Hobbes says in Chapter XXXVIII (38) that there is no such thing as an immortal soul outside a body, and that immortality of humans will only be achieved when they are resurrected (in their bodies) after the last judgment. Our immortality at that point will be lived on earth, not in some other place like heaven. In section 6 of that chapter he suggests that the Scripture says where people “remain until the resurrection” is somehow in the earth, buried. Now it’s not clear exactly where he’s going with this, but one option is that our matter dissipates into other matter after we die, body and soul. And then that God can resurrect us entirely at the judgment.

    2. In Chapter xliv (44), section 15, he says that surely God can resurrect people from the dead, even if they were dust: “For supposing that when a man dies, there remaineth nothing of him but his carcass, cannot God, that raised inanimated dust and clay into a living creature by his word, easly raise a dead carcass to life again, and continue him alive forever, or make him die again, by another word?”

    3. Also in Chapter 44, section 15, he defines soul: “The soul, in Scripture, signifieth always either the life or the living creature, and the body and soul jointly, the body alive. In that section he pretty clearly states that what it means to have a soul is to have “body and life.” So the soul would be whatever matter it is, or arrangement of matter, that gives other matter the ability to move from within (the definition of life). He goes on in Section 16 of chpt. 44 to suggest that though people have thought the soul must exist somewhere between the time of death and resurrection (and that the Catholic church invented purgatory for this reason), he doesn’t think this needs to be the case. Which makes sense if you think of the soul as that matter (or arrangement of matter) that provides for life in some way. When the body is dead the soul is not there anymore, if it’s identified with life.

    4. He says in Chapter 39, sect. 5 (p. 316) that after the resurrection “the bodies of the faithful … shall be not only spiritual, but eternal; but in this life they are gross and incorruptible.” This suggests that there will be some different matter that makes up our bodies after the resurrection. That it will still be matter is clear from Chpt. XLVI (46), sect. 15 (p. 459), where he says that everything that is part of the universe (which is just defined as “all”) is body. “Nor does it follow from hence that spirits are nothing. For they have dimensions, and are, therefore, really bodies,” he says. In Chpt. 44, section 27 (p. 427) he again says that after the resurrection “the faithful shall rise again, with glorious and spiritual bodies,” which will not require that we eat and drink, or go through “generation” (birth).

    From all of this I’m thinking that for Hobbes, what happens to our matter after death is that it changes into other matter. And then at the day of judgment, God creates new bodies for those who are to go on into eternal life (which is not everyone; you can look up in Chapters 38 and 44 what he thinks will happen to those who have not lived as they should). This seems to me to keep to the law of conservation of mass.

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