Death of metaphors in life science?

Metaphors appear as an essential part of any theorizing practice. Everyday conceptions and folk theories use everyday metaphors. Science utilizes metaphors that have been drained of their ‘poetic’ potential to a degree that we can say they have been conventionalized to death, at least when used by experts in the field. The metaphor has evolved from a ‘living’ to a ‘dead’ metaphor (Black, 1994). However, when experts use these ‘dead’ metaphors in communication with non-experts the metaphors may experience a “poetic” rebirth and lead to miscommunication and misunderstanding, which in particular can be the case for beginner students of an abstract area like molecular life science.

That a metaphoric expression can be conventionalized in a way that makes us forget its metaphoric origin is a normal and sound process. It would be inconvenient to constantly think about the metaphoric origin of a well-defined concept. Cell biologists uses the term “cell”, for example, in their daily practice in its biological sense without any need to think about its metaphorical origins from an analogy between the cells of a plant seen using a microscope and the cells of a monastery. Beginners in a field, on the other hand, lack the experience of using a term of metaphorical origin in its subject-specific sense, and may therefore be more cognitively affected by the underlying metaphor than the expert. In other words, they may not yet have ‘killed’ the metaphors in the area. This poses an educational challenge for the science educator, who must be aware that a novice student understands an expression like ‘covalent bond’ differently from an expert who has a thorough experience of, for example, reasoning about chemical binding, molecular structure, and interaction between molecules.

A metaphor can be regarded as a good metaphor for different reasons. From a rhetorical point of view a good metaphor should be an image that captures the attention of the listeners by means of its poetic or otherwise striking qualities. From a scientific point of view a good metaphor is an image that makes an abstract scientific concept tangible and possible to handle by scientists, without distorting the scientific content. From a didactical point of view a good metaphor is an image that can be understood and used by the learners, giving a good approximation of the scientific content, without misleading the learners in their thinking. From the perspective of the student, a good metaphor is a metaphor which links the scientific content to his or her prior experience, in other words to the life-world of the student. The use of metaphoric language can constitute a bridge between the students’ prior language and a scientific language. In some cases, these different points of view merge more or less unproblematically into one in science education. On other occasions it can be a question of context and audience whether you ought to stress the rhetorical, didactic, or scientific aspects of the use of metaphor; or whether you should take the perspective of the scientist, the policy-maker, the teacher or the student. A balanced use of metaphors needs to consider all these perspectives.