One of the most important principles of philosophy in the perennial tradition
is the view that all the things of nature act for the sake of an end. The world in which we
live is not at bottom a world of chance or chaos. Rather, natural things are purpose driven things,
and every agent acts for the sake of an end – each according to its own natural kind.
Yet, many people deny that there is teleology, or final causality, in nature,
and think modern science confirms their position. So, let’s explore the question.
Nature gives us an abundance of example of things acting for an end or purpose. Eyes are for the
sake of seeing, ears are for the sake of hearing, and the heart is for the sake of pumping blood.
Squirrels gather nuts in the summer in order to store food for the winter,
woodpeckers peck away at trees in order to find insects to eat, and bees gather pollen
in order to make honey. Trees put down roots in order to gather nutrients from the soil,
and also spread their leaves to soak up sunlight. Sunflowers are an even more dazzling example.
They track the sun from morning until evening in order to take in as much light as possible.
And even things that at first glance might seem pointless, like the human tailbone,
in fact have many important functions in the body. In a previous video on the four causes,
we explained Aristotle’s famous list of causes or ways to answer the question why.
The material cause is that out of which a thing is made, the formal cause is what makes the thing
to be what it is. The efficient cause is that which produces motion or rest in something,
and the final cause is that for the sake of which a thing is or is done. Now let’s focus
on the final cause, and explanation in terms of the end. Why do birds have wings? Birds have wings
for the sake of flying and perhaps for other ends too. Why do deciduous trees have leaves?
For the sake of photosynthesis and perhaps other ends too. Why do animals have an immune system?
In order to resist pathogens and perhaps for other ends too such as for recovery from infection.
Now, the Greek word for end is telos. So, when we explain something in terms of its end,
or final cause, it is called a teleological explanation. Teleological explanations can
be used to understand either the parts of a thing, or the whole.
Eyes, for example, are parts of the whole organism and these parts are for the sake of seeing.
But organisms as a whole also have their ends, and the end of the whole organism may be understood
in two ways. In one way, things act for sake of their own optimal flourishing. In another way,
things act for ends beyond themselves within the larger natural system in which they serve a role.
Insects, for example, develop and act in order to reach an optimal state in which each one is fully
operational as an insect – whatever sort of insect it might be. Being fully operational for an insect
means carrying out the activities proper to the kind of things insects are. Insects crawl
around or buzz around, for example, and eat particles of various sizes.
But insects also serve further ends within the ecosystem. By going around and eating particles,
for example, insects clean up the environment. If insects did not go around eating particles, the
world would be covered in many layers of sludge. Insects are like nature’s sanitation engineers.
As such they play an important role in the world. Now teleological explanations like all of these
are in many respects just a form of common sense thinking about nature,
but such explanations raise a lot of questions – good questions. When sunflowers track the light of
the sun over the course of the day or when insects crawl around, do they know what they are doing? If
they do not know what they are doing, then how can they act for the sake of an end? And what about
inanimate things like water or atoms? Do they have ends too? Such questions call for distinctions.
There are three senses of the term end. In the first and most obvious sense of the term, an
end is a person’s conscious intention or purpose for freely acting. When a person drives a car,
for example, the end is to get to his or her destination. Now, perhaps someone might just
go joyriding, but then joyriding would be the intention or the end of the driving around.
In either case, the end in this first sense is a conscious intention of a person. Ends in this
first sense are perhaps more properly called an intention or goal or purpose,
and only persons have ends in this sense. But in a second and broader sense of the term,
an end is not something consciously intended, but merely a terminus of action. In the body,
for example, red blood cells circulate to the lungs where they pick up oxygen, and then carry
the oxygen to tissues where the red blood cells release the oxygen. The release of the oxygen is
the terminal point of the process, and it explains the activity of the red blood cell. When such a
terminal point of a natural process or activity explains why the process or activity goes on,
then the terminus is a final cause even though the various substances and agents involved
do not know what they are doing and the various activities or processes they are carrying out are
not conscious or deliberate activity. In the third sense of the term,
an end is the good or perfection of a thing. When an apple tree bears apples, it reaches a peak of
its perfection and works towards perpetuating its species. When an apple tree does not bear apples,
we ordinarily say “something is wrong with it.” It is blocked from being and becoming what it is and
is supposed to do by nature. The end or final cause is thus a measuring stick or criterion
of a thing’s overall condition, health, and flourishing. Teleology in nature is a marvelous
thing and a cause for wonder. Science does not deny the reality of it. On the contrary. Science
textbooks are filled with teleological language and explanations, expressions like “tending to,”
“in order to,” “so that,” “for the sake of,” “functions to,” “or simply “functions.”
In using such language, science textbooks are not deceiving us but naming something real. They are
naming actual teleological activity that in fact goes on in nature. In later videos, physicists
will provide examples of teleology at the quantum level. Final causality is a cause for wonder.
How could it be that things without intelligence can and do act for the sake of an end? This
question is at the basis of Thomas Aquinas’s fifth way for demonstrating the existence of God.
Reason points us to the answer: behind the natural world so full of teleological activity,
there must be a higher Mind. God – who directs all things, and orders all things well.
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