Teleological Reasoning in Science

Language suggestive of teleological reasoning appears in the scientific literature about evolution. Such language is entrenched in the very formulation of evolutionary theory. It is dangerous to allow any trace of teleological reasoning when doing evolutionary science. Therefore, such language ought to be eliminated.

Consider these statements about the fringes on Salamander toes:

1. The fringes on Salamander toes evolved in order to enable Salamander's to run faster in sandy environments.
2. In sandy environments, Salamander's with fringed toes run faster than Salamander's without fringed toes.

If you were writing a scientific paper about fringed Salamander toes, which statement would you use? In Not By Design: Retiring Darwin's Watchmaker (2009), John O. Reiss argues that undertones of teleological reasoning makes the first statement unacceptable in scientific writing. He champions statements like the second.

Teleological reasoning, to very briefly summarize, is reasoning that explains an effect (such as the existence of Salamander toes) by citing a goal, or a purpose, as a cause of that effect.

Though it is not immediately clear how the first sentence is suggestive of teleological reasoning - it would take careful work to de-construct the sentence and show just where teleological reasoning enters the equation - I think that the phrase in order to is where we should focus our attention.

Consider these sentences which also use the phrase in order to.

1. John turned off all the lights before he left in order to save electricity.
2. John does push-ups every day in order to stay in shape.

It is clear that a goal, or desire, is playing a key role in causing John's actions. In certain contexts, such as the every day context of explaining John's actions, it is acceptable to cite desires or goals as causal factors.

However, when writing for the scientific community about non-conscious processes, such as evolution, it is important to exclude any trace of teleological reasoning. It is difficult to do this at times because, as Reiss argues in his book, teleological reasoning has entered into scientific discussions about evolution partially by way of word choices that are highly entrenched in the language of evolution, such as the term adapt.

It is important to exclude teleological reasoning from science because it is bad science to explain, for example, a non-conscious process such as the evolution of Salamander toes by citing goals or desires as a causal factor. Fortunately, this is not the problem at hand. The problem at hand is one of good scientists doing good science, but who, in the communication of their ideas, use careless language that is suggestive of teleological reasoning. This problem is, according to Reiss, ubiquitous within scientific literature.

One danger of using such careless language is that a door is opened for scientists doing poor science, and whose bad theories may be difficult to discredit just because they share the same language as the good theories.

Evolution, in theory, is a non-conscious process. It ought to be formulated, written about, and discussed as such.

Resources

Reiss, J. O. (2009). Not by Design: Retiring Darwin's Watchmaker. University of California Press, Berkeley. Amazon link.