Literature Review 2.1 Overview of Metaphor Studies 2.1.2 Ancient Greek Period Metaphor is generally defined as a figure of speech for rhetoric effect, which refers to one the thing by mentioning another. The earliest study of metaphor can be traced all the way back to Aristotelian era. The ancient Greek philosopher Aristotle devoted himself to this language phenomenon over 2000 years ago and is regarded as the forerunner and representative of the traditional school of metaphor study. Aristotle gave his definition of metaphor in Poetics and Rhetoric: Metaphor consists in giving the thing a name that belongs to something else; the transference being (i) either from genus to species, or (ii) from species to genus, or (iii) from species to species, or (iv) on the ground of analogy. (Poetics, from Hawkins, 1980) The school of metaphor study represented by Aristotle is commonly known as comparison theory. As his explanation has shown, metaphor is confined to the area of rhetoric usage, closely related to another rhetoric device i.e. simile. Two objects can be linked together based on their similarities even though they belong to different genus or species. For example, as in My lawyer is a shark, the noun ”lawyer” denotes some specific human being while ”shark” refers to an aggressive animal predator. ”My lawyer” and ”shark” thus conjoins into a sentence based on their shared feature--aggressiveness. The use of metaphor is considered by this tradition school of thought as a literal skill mastered by educated men, far beyond the grasp of ordinary people who lacked basic education. 2.1.2 From the Cognitive Perspective Cognitive linguistics as a new sub-field of linguistics came into being and has been at the dd focus of study since 1950s. The study of metaphor has gradually spilled over its rhetoric border into the cognitive field. The metaphor study has been approached from a cognitive viewpoint since the epoch-making publication of Metaphors We Live By by American linguists Lakoff and Johnson in 1980. The conceptual metaphor theory posited by them is that metaphors are largely the children of human beings#8217; conception. They are the projections of our thoughts and values, permeating in the everyday use of language. Their pervasiveness and ubiquity is to such a great extent that the speakers of that language simply don#8217;t realize their very existence. In their seminal work Metaphors We Live By, Lakoff and Johnson present their views on the difference between traditional metaphor study and the newly-forged conceptual one: Metaphor is for most people a device of poetic imagination and the rhetorical flourish a matter of extraordinary rather than ordinary language. Moreover, metaphor is viewed as characteristic of language alone, a matter of words rather than though or action. For this reason, most people think they can get along perfectly well without metaphor. We have found, on the contrary, the metaphor is pervasive in everyday life, not just in language but in thought and action. Our ordinary conceptual system, in terms of which we both think and act, is fundamentally metaphoric in nature. Metaphor is typically dissected into two segments: TARGET DOMAIN and SOURCE DOMIAN. According to Lakoff and Johnson (1980), the target domain is the experience being described by the metaphor and the source domain is the means being used to describe the experience. For example: You demolished all my arguments. This sentence is derived from the metaphor ”Argument is war”, in which argument is the source domain while war serves as the means to describe it. Lakoff and Johnson posited three types of metaphors in their book Metaphors We Live By: Structural Metaphors, Orientational Metaphors and Ontological Metaphors. Structural metaphors refers to the construction of one concept according to another. This means that structural metaphors are grounded in our experience and imply how one concept is metaphorically structured in terms of another. As has mentioned above, ARGUMENT IS WAR leads to an English expression like ”He attacked every weak point in my argument.” ”Your claims are indefensible.” ”His criticisms were right on target.” Orientational metaphors is based on the spatial orientation. ”They are characterized not so much by structuring one concept in terms of another, but by a co-occurrence in our experience. The orientational metaphors are grounded on an experiential basis, which link together the two parts if the metaphor. The link verb ”is#8217; ,as a part of the metaphor, should be seen as the link between two different co-occurring experiences. For example, MORE IS UP. This metaphor is grounded in the co-occurrence of two different kinds of experiences: adding more of a substance and perceiving the level of the substance rise.” (Hu,2017:130) For example, HAPPY IS UP; SAD IS DOWN: a.I#8217;m feeling up. b.That boosted my spirits. c.You#8217;re in high spirits, d.I#8217;m feeling down. e.I#8217;m depressed. f.My spirits sank. In this case, metaphors are closely related to human#8217;s physical posture. When we#8217;re happy, the posture of our bodies usually stand erect, whereas they fall into a drooping fashion when we feel sad. Ontological metaphors mean that human experiences with physical objects provide the basis for ways of viewing events, activities, emotions, ideas, etc. , as entities and substances. Ontological metaphors can serve various purposes. By ontological metaphors we give bounded surfaces to less clearly discrete entities (mountains, hedges, street corners) and categorize events, actions and states as substances. Take the experience of rising prices as an example, which can be metaphorically viewed as an entity via the noun inflation. This gives us a way to refer to experiences (Lakoff Johnson, 2003:27): INFLATION IS AN ENTITY a.Inflation is lowering our standard of living. b.We need to combat inflation. c.Inflation is hacking us into a corner, d.Inflation is taking its toll at the checkout counter and the gas pump. e.Inflation makes me sick. Treating those inanimate subject matters as something endowed with thinking ability and behavioral power helps mankind better understand it and deal with it in a much more serious way. As in Hu#8217;s words, ”qualify it, identify it, treat it as a case, act with respect to it, and even believe that we understand it. Ontological metaphors are necessary for dealing with human experiences.” (Hu, 2017:132) 2.2 Previous Research at Home And Abroad 2.2.1 The Definition And Role of Idioms According to Merriam Webster, idiom is defined as an expression in the usage of a language that is peculiar to itself either grammatically (such as#160;no, it wasn't me) or in having a meaning that cannot be#160;derived#160;from the#160;conjoined#160;meanings of its elements (such as#160;ride herd on#160;for "supervise")., a language peculiar to a people or to a district, community, or class. Idioms, as the crystallization of a particular group or people living in a certain environment, observing unique social conventions, are expressions loaded with meanings. As the definition has revealed, idiom is a unique expression particular to a region or people the meaning of which is not the sum total of its components. Therefore, we cannot infer its meaning from its constituents. Idioms take up a large proportion of native speakers#8217; everyday usage. Usually in the form of phrases, they convey speakers#8217; emotions, intentions, opinions and thoughts in a succinct and precise manner. As language is a window into which we glimpse its speakers#8217; mind, idioms provide a convenient channel to know about that group#8217;s mentality. 2.2.2 Studies at Home And Abroad There have been many studies centered on idioms both at home and broad given that idioms provide a unique perspective into language usage and the culture in question . Yet previous studies of idioms mainly centered on their categorizations, semantic meanings, cultural origins and associations. The four major perspectives on the study of idioms overseas are structural, functional, cognitive and psycholinguistics point of view. Structural studies led by Saussure focus on the linguistic forms. From structural perspective, idioms are composed of smaller componential units and their meanings are not predictable from these component parts. Functional studies regard the usage of idioms as a kind of speech act used in certain linguistic communication. Cognitive and psychological studies are closely related with each other and carried out in a much similar way. Scholars dedicate themselves to studying the role of cognition in comprehending idioms. Since cognitive linguistics is the focus of interest and attracts much attention in linguistics community in recent decades, the thesis approaches the idioms in accordance with this perspective. Studies at home can be generally classified into three perspectives from linguistic perspective, from the cultural perspective and from the contrastive perspective. The studies from the linguistic view mainly focus on translation issues. Then the studies from the cultural perspective try to uncover the cultural influences and cultural connotations associated with idioms. The contrastive studies on idioms mainly work on the similarities and discrepancies between Chinese idioms and English idioms. As idioms are the children of a specific culture, cultural factors play a key role in all the study analyses. However, the conceptual metaphor study of idioms, which is closely related to cognitive linguistics, has not been much touched upon. Therefore, the thesis is intended to carry out a tentative probing into the conceptual metaphor mechanism underpinning the idioms from a cross-cultural perspective. The metaphor study of idioms shall offer us a new way of understanding these brilliant expressions, thus leading to a better employment of idiom.