1.2　Role of metaphor

　The reasoning based on normal experiences deals with a concrete category. But how can one deal with an abstract category in a literary work? When an author seeks to use an abstract idea to represent any concrete object, a relationship is established between the abstract idea and the concrete object, which is called a metaphor.
　To represent a metaphor graphically, a map from a source domain to a target domain is established. This mechanism creates an abstract idea and is therefore also considered as the expansion of a meaning by language. Some ideas become habitual, and a mapping is established at the level of thought and concept. The problem does not comprise any expression in language.
　For example, one can use “A is B” to represent a metaphor. Here, A is a target domain and B is a source domain. A metaphor serves to create an impression of something otherwise unnoticeable. The structure of the source domain is also mapped in the form of integrating a target domain, thus forming an invisible structure. Human reasoning would serve to identify the related matters in the structure.

Metaphor (1): If Huanghelou is a symbol for Wuhan, the first bridge is Wuhan’s aorta.

　The first half of the conditional (1) uses a metaphor and the second half uses the reasoning from it to explain the corresponding element. The problem of (1) is not true-false, but something like it. Reasoning by metaphor is also a discovery method toward a solution. An analogy could certainly be effective, even if conceptual domains are worlds apart. There is no guarantee that it is true, but if one applies existing knowledge to understand an unknown field, one is at least headed in the right direction.
　Furthermore, cognitive linguistics pursues research on the methods of understanding while receiving information. The method of seeing the world objectively differs by society or culture because the level of different thought can be studied as linguistic difference. The research of Sapir and his disciple Whorf on language and thought is the most widely known.
　
Sapir-Whorf hypothesis: The structure of the mother tongue has an effect on thought independent of a language, especially the cognitive ability such as categorizing or reasoning.

　The common interpretation of this hypothesis holds that a language has considerable effect on thought. But which aspects of thought does a language affect? The mechanism of perception and memory is not determined by language. For thought, the higher cognitive ability of how to perceive things seems to be the problem. When I consider which memory is stored easily or how memories connect with each other, I find the outline and distinction of a speech community.

花村嘉英著（2015）「从认知语言学的角度浅析鲁迅作品－魯迅をシナジーで読む」より translated by Yoshihisa Hanamura