>DNAunion: I can believe I gave in and spent hours scanning through my
>college
>texts for forms of the word "tendency" in order to counter my opponents'
>claims that I am wrong in my usage: but I did.
I can't believe that I gave in and browsed the Calvin archives to read
DNAUnion's posts, having kill-filed him. But I did!
>To show that tendencies and behaviors can differ, I originally presented a
>valid example. However, it wasn't very relevant to the topic. My example
>dealt more with probabilities: men *tend* to be stronger than women, but
>there are many women that are stronger than some men. Each individual man
>does not himself tend to be stronger than women: some men are, some are
not.
>But taken as a whole, there are more men that are stronger than women than
>there are women that are stronger than men. That is, men as a group are
>*more likely* to be stronger than women than women as a group are to be
>stronger than men. My example directly related "tend" with "are more likely
>as a whole". This is not the type of tendency I needed to discuss.
>
>
>Therefore, I will now present material that directly relates to the kind of
>tendency involved in our discussions: ones in which a tendency affects all
>objects/processes of the same type, but that can differ from the actual
>behavior of the object/process if another force/tendency enters into
>consideration.
>
>
>First, I will start off with a quick coverage of an intuitive,
hypothetical,
>everyday example.
>
>
>At a local gym, a weightlifter lies down on a flat bench which has two
>vertical, sturdy bars that support at nearly full-arms reach a barbell
>weighing 300 lbs. He forcefully contracts his chest (and other) muscles and
>lifts the barbell, followed by locking out his elbows. At this point (and
>indeed, before and after), because of the attractive force imposed on the
>barbell by gravity, the tendency of the barbell is to take up a position as
>physically close to the Earth's center of mass as possible (i.e., its
>tendency is to move towards the floor and to remain there once it achieves
>this). As the man unlocks his elbows and slightly relaxes his muscles, the
>barbell begins a slow descent. Why? Is the man *pulling* the barbell down
>towards the ground? No. He is simply allowing the barbell to move according
>to its natural tendency. Once the barbell is just above his chest, the man
>tenses his muscles again, applying an upward-directed force: the barbell
>slowly rises. But wait a minute. Why must the man strain so hard if the
>barbell doesn't have a tendency to move downward towards the ground?
>Obviously, the barbell still DOES have that tendency - it opposes the man's
>attempts to separate it farther and farther from the Earth's center of mass
>at every second. But how can that be - if the barbell has the tendency to
be
>moving downward, imposed on it by gravity, then how could it possibly be
>moving upward? Because its *behavior* can be different from its *tendency*
>if a sufficient opposing force is applied (note that the force of muscular
>contraction applies a tendency to the barbell: as mentioned below, tension
>in
>muscles *tends* to cause objects to move). So it is one tendency/force
>opposing another: the behavior of the system (man and barbell) depends upon
>which force overcomes the other. The tendency for the barbell to take up a
>position as physically close to the Earth's center of mass exists before
the
>man lies down on the bench, while the man first hoists it of the rack,
while
>the man allows it approach his chest, and even while the man strains to
lift
>it away from his chest. The tendency of the barbell itself remained
constant
>throughout the process, even though the behavior of the barbell (actually,
>the barbell-human system) changed.
Unfortunately, this example is no different in principle from your
teeter-totter example.
When the man exerts an upward force on the barbell which is greater than the
force of gravity, its tendency/behaviour is to rise. When he exerts a
smaller force than the force of gravity, its tendency/behaviour is to fall.
You are arguing that the effect of gravity is a tendency, but the effect of
muscles is not. Why? This is an arbitrary distinction.
Now, you might argue that the barbell has many tendencies at the same time:
it has a tendency to fall (due to gravity), a tendency to rise (due to
muscles), a tendency to stay still (due to inertia), a tendency to bend (due
to the weights on the ends of the bar), a tendency not to bend (due to the
rigidity of the bar), etc. The actual behaviour of the barbell is then the
net result of all these tendencies. If you wish to take this position, then
I accept your use of the word tendency. But, in this case, you can't
characterise the tendency to fall as *the* tendency of the barbell; it's
just one of many tendencies.
We can see the same sort of issue in your final example. (I'll skip your
other examples as they all seem to be making the same point.)
[...]
>"The Moon in motion tends to follow a straight-line path, according to
>Newton's First Law, the law of inertia. The fact that it follows a curved
>path meant to Newton that a force must be pulling it out of its
>straight-line
>path, just as the key described in Section 5-7 is deflected from its
>straight-line path. (Melvin Merken, Physical Science with Modern
>Applications: Fifth Edition, Saunders College Publishing, 1993, p82-84)
>
>
>Same as above. The tendency of the Moon itself is to fly off in a straight
>path. But its behavior differs from its tendency because the gravitational
>affects of the Earth influence the Moon's motion.
I say the the word "tend" is being used here in the same sense that I've
described above. It refers to the effect of just one particular law (or
force) which is acting on the object, while ignoring others. If we use the
word in this sense, then the Moon has more than one tendency. According
to the Law of Inertia, the Moon tends to follow a straight-line path.
However, according to the Law of Gravity, it tends to fall towards the
center of the Earth.
In other words, to say "the Moon in motion tends to follow a straight-line
path, according to Newton's First Law" is a shorthand way of saying "the
behaviour of the moon in the absence of any laws other than Newton's First
Law would be to follow a straight-line path".
When you say that a system has a tendency to act in a particular way, all
you're saying is that there is a law (or force) which *would* cause the
system to behave in that way, in the hypothetical absence of other laws (or
forces). But this is a hypothetical statement which is contrary to fact. In
fact, other laws (or forces) *do* exist.
With this understanding of what we mean by tendency, let's return to the
SLOT. We can now say that the tendency of an isolated system, according to
the SLOT, is to increase in entropy.
And what about non-isolated systems, which are the ones we're interested in
here. You apparently want us to accept that non-isolated systems have a
tendency to increase in entropy. But the SLOT says no such thing, unless
there is some implicit qualifier, as in the Moon passage above.
I suppose you could have in mind the qualifier "in the absence of a
surrounding environment with which the system can exchange energy". But
that's just equivalent to the statement above about isolated
systems, and we're not dealing with an isolated system in abiogenesis.
I suppose you could have in mind the qualifier "in the absence of any
processes
which reduce entropy". But that's leaves us with a statement that is little
more than a tautology.
So, what *do* you mean?
Richard Wein (Tich)
--------------------------------
"Do the calculation. Take the numbers seriously. See if the underlying
probabilities really are small enough to yield design."
-- W. A. Dembski, who has never presented any calculation to back up his
claim to have detected Intelligent Design in life.
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