Teleological explanations
A topic in Learners' conceptions and thinking
This page discusses teleology and teleological exaplanation. I have also compiled a list of examples of teleology in science that I have noticed in my reading and in broadcasts:-
Read examples of teleology in science.
A form of pseudo-explanation?
Explanations constructed by learners sometimes have the superficial form of an explanation, but are deficient as scientific explanations. These constructions have been called 'pseudo-explanations', and are of various forms (Taber & Watts, 2000).
Read about pseudo-explanations
Scientific explanations are expected to draw upon scientific concepts and natural processes/mechanisms. However, students may explain a phenomenon in terms of the outcome meeting some end deemed desirable (the sun shines to make the plants grow) – such an explanation is teleological. A teloeological explanation amy reflect actual teleogloical thinking (which could perhaps sometimes be cosndeired as a kind of magical thinking), or may reflect lack of care in phrasing an idea.
Teleology
A teleological explanation is an explanation in terms of ends or purposes. For example, consider the following hypothetical example,
"continental drift occurred so that there was a good distance between Africa and South America"
Given that Africa and South America are thought to have once been contiguous we might explain their current separation by continental drift…
…but to explain continental drift as occurring so that the continents were separated suggests that occurs for a purpose
This implies some kind of knowing agent with a purpose.
Perhaps the two tectonic plates carrying those land masses wanted to be apart, and so they moved apart to bring this about. That would be an example of anthropomorphism: treating inanimate objects as if they were people who deliberately acted in the world. (The idea that natural features such as volcanoes, clouds, the oceans might be alive was once common, but is not part of a scientific view of the world. Poets may choose to communicate their ideas with figurative language reflecting such ideas, but scientific accounts are expected to be more literal.)
Or, perhaps there is some divine power who set up the universe with certain ends in mind, and brought about the current state of the world through various mechanisms, including plate tectonics. Science does not have anything to say about such matters (though some individual scientists certainly have views), but scientific explanations have to be about the natural mechanisms, following the observed laws or regularities in nature, without regard to any supernatural ultimate causes. (A belief that the world was set up by God who created everything, including all the natural mechanisms, does not need to be in conflict with the scientific account – but is not part of the remit of science which is concerned with natural phenomena and causes.)
So a scientific explanation may involve such matters as density, temperature, buoyancy, force, gravity…but does not rely on notions of purpose or desired ends.
Admitting tautology
This does not mean that teleology is never allowed in explanation. Aristotle counted teleology as one of the types of explanation that can be useful sometimes – but in science we should be wary. Consider the following example:
"A pocket watch keeps the time because it has been designed to be used as a clock"
In a sense this is true. Someone designed the watch to have a certain function. It is not an accident that the watch keeps time – it was built for that purpose. That is part of the story – it explains why someone would go to the effort of building such a complex and delicate mechanism.
However, a scientific explanation of why the clock kept time would be in terms of the gears and the driving mechanism – that is in terms of forces acting on material parts.
That would not be the whole story. That might be a physicist's focus, but a material scientists would think that an important part of the explanation was in terms of the properties of the materials used – being hard wearing, not so brittle that parts break under moderate stress, the elastic nature of the spring, using parts that responded similarly in response to temperature changes, perhaps the use of a light oil to lubricate moving parts and so reduce wear… Aristotle would have recognised this as the 'material cause'.
A full explanation of the watch keeping time would have included what it was intended to do and so designed for, how it was constructed and by whom, what material it was made up form, and how the mechanism works in terms of such scientific concepts as energy, force, torsion/tension…
When studying natural phenomena (a plant in the garden, a stream changing it course, shooting stars, a new disease…) we might be interested in their material composition, and how they were formed, as well as how they function. But teleological explanations that rely on assigning some purpose or end goal to nature are not admitted – they might be considered cheating!
Cheat explanations
- "That river changed course to divert water to the village"
- "The seeds blew into your garden so you would have pretty flowers to look at in the Summer"
- "The moon orbits at that distance from the earth so that we can get some perfect eclipses"
- "It gets dark at night so that we can sleep more easily"
- …
Such teleological explanations do not really explain anything, but rather avoid any real understanding of the natural phenomena.
"…it is crucial to realise that there is a huge taboo against a teleological understanding of organisms and/or their organs being genuinely 'for' something – except, of course, for surviving, which is not an explanation in terms of immediate cause and effect, but is allowable because natural selection in the past gives the impression of present…harmony."
Dorion Sagan
The problem with biology (and discussing functions)
Teleological explanations are sometimes found in discussions of biological topics. Living organisms are incredibly complicated, and only remain alive because the organism is a system which is able to maintain life by keeping the coherence of the organism, and having processes that operate to prevent the system returning to an equilibrium with its surroundings (your body temperature is fairly constant, even when it is cold outside; chemicals are actively concentrated in some places…).
It is very easy to think of biology in terms of functions. The alimentary canal absorbs food, the lungs carry out gaseous exchange, muscles move the limbs, the backbone protects the spinal cord, and so on. (Similar points can be made about the parts of plants.) The kidneys excrete waste products and maintain the water levels. The heart pumps blood,and so oxygen and glucose, etc., around the body…
These are descriptive statements, but it is very easy to slip into slightly different language that suggests purposes:
- We have kidneys to excrete waste products and maintain the water levels
- We have a heart to pump blood around the body
- We have a backbone to protect the spinal chord and to help us walk
- etcetera….
Are these statements wrong? It seems harsh to suggest that such statements are actually false, but they seem to suggest that anatomic features and organ systems have a purpose, not just a function. Strictly, science observes that various features have evolved and natural selection has ensured that those retained are, on balance, adaptive. This language can therefore be misleading as it may suggest that evolution is purposeful (that is, that somehow evolution has ends in minds – "it would be good to judge distance, so let's go for binocular vision" – where the scientific account sees natural selection as 'blind'.)
Consider this example
This* seems to suggest that evolution has a purpose (here, to avoid different species trying to breed) and a change occurs (the two species diverge in their traits, become more distinct) in order to achieve that end goal. This may seem a reasonable narrative, but is actually completely contrary to the scientific account of how natural selection occurs.
Read about 'Learning about natural selection and denying evolution'
* This example was given by an evolutionary biologist who was engaged in communicating science to the public.
Read about "Science in public discourse and the media"
And a social psychologist talking on a radio programme suggested:
Teleology as a methodological heuristic
The wide adoption of teleolgoical langauge in biology can be understood as a kind of methodoloical choice – given that understanding organisms qua organisms (that is, as entities that maintain existence as individual living wholes despite the entropic trendency to disruption and decay) requires explaining how the system is 'actively' maintained; it makes sense to adopt the viewlpoint of seeing functions in structures,
"To employ a teleological method in the study of living organisms means only that we examine the processes of life so as to discover to what extent the character of preserving wholeness manifests itself."
Ernst Cassirer, 1950
Of course, when this lnaguge is used in public texts accessed by non-specalists it may be understood to imply purpose and deliberate design even if that was not intended.
"In establishing this idea that life is ordered toward wholeness we are simply concerned with a phenomenon that can be demonstrated by purely empirical methods. No theoretical skepticism can prevent our recognition of this 'ordering' as something factually given. Scepticism can be directed toward the interpretation which science may venture to give this basic phenomenon, and here Bertalanffy [Ludwig von Bertalanffy] was emphatic that the concept of purpose is not the best means for the description of the actual facts because it leads almost unavoidably to false anthropomorphic notions."
Ernst Cassirer, 1950
Vitalism as teleology
The perspective of vitalism, a common perspective prior to modern biology suggesting there is some special kind of life-force inherent in living things, may be seen as teleological. This perspective was reviewed by Ludwig von Bertalanffy, in the terms:
"In the embryo, and similarly in other vital phenomena, a factor is active which is fundamentally different from all physics-chemical forces, and which directs events in anticipation of the goal. This factor "which carries the goal within itself", namely the production of a typical organism in normal as well as in experimentally disturbed development, was called entelechy by Driesch, using an Aristotelian notion."
Bertalanffy, 1952/2014, p.6
Work cited:
- Bertalanffy, L. v. (1952/2014). Problems of Life. An evaluation modern biological thought. Mansfield Centre. (New York: Wiley. 1952)
- Cassirer, Ernst (1950) The Problem of Knowledge. Philosophy, science, & history since Hegel. (Translat. William H. Woglom & Charles W. Hendel) New Haven & London: Yale University Press.
- Taber, K. S. & Watts, M. (2000) Learners' explanations for chemical phenomena, Chemistry Education: Research and Practice in Europe, 1 (3), pp.329-353. [Free access]
