On The Conceptual Metaphors And Their Discourse Coherence In Commencement Speeches

Metaphor is so prevalent in daily life that it can be found not only in our everyday language,but also in our way of thinking.The traditional metaphor theory considers metaphor as a rhetoric of language,thus laying the foundation for rhetorical studies in studies of metaphor from onward.With the emergence of cognitive linguistics,Lakoff and Johnson(1980)published a masterpiece Metaphors We Live By,in which they hold that metaphor serves as a rhetorical device,and even as a significant cognitive mechanism and thinking mode constructing the concept world of human beings.Henceforth the conceptual metaphor theory has been gradually enriched and developed.As the studies on conceptual metaphor have been shifted from vocabulary,phrase and sentence to discourse level,the greater importance is attached to the relationship between metaphor and discourse coherence.Scholars have explored the conceptual metaphors in literary texts such as novels,prose and poems from different perspectives,but few studies have been conducted on speech discourses,especially educational speech discourses.As a special discourse form to reflect our everyday life,speech discourse is to be carried out in specific space and time in order to share ideas and influence others.As an important part of college graduation ceremony,commencement speech is one kind of educational discourses with strong educational significance and value of appreciation,aiming to encourage graduates to shoulder their responsibility and instruct their future life.This paper is to conduct a special study to answer the following two questions:1)What are the common conceptual metaphors used in commencement speeches?2)How are these metaphors connected with one another to construct a persuasive educational discourse?On the basis of Conceptual Metaphor Theory proposed by Lakoff and Johnson(1980),20 commencement speeches in Harvard University from 1998 to 2017 were selected as the data to explore conceptual metaphors in these speeches.Firstly,combining the metaphor identification procedures put forward by Charteris-Black(2004)and Pragglejaz Group(2007),the conceptual metaphors that appeared in the data were identified and categorized,and main types of conceptual metaphors commonly used in such speeches were summarized in accordance with quantitative and qualitative analysis.Besides,the speech delivered by Zedillo at Harvard University in 2003 was selected as the data to discuss how the two characteristics systematicicty and coherence are manifested within a single conceptual metaphor and in different conceptual metaphors,so as to further explore the ways in which conceptual metaphors are used to construct discourse coherence in such kind of discourse.According to the present study,the most commonly used conceptual metaphors in the data are journey metaphors,war metaphors,container metaphors and building metaphors.Among them,journey metaphors are the most frequently used and account for the highest percentage among the other four types.In addition,two prominent characteristics of conceptual metaphors,namely,systematicity and coherence contribute to the discourse coherence of the data.Such coherence is not only found among metaphorical expressions in one conceptual metaphor,but also between two conceptual metaphors sharing one target domain or one source domain and among different conceptual metaphors as well.The present study further confirms the universality of conceptual metaphors and their special function in discourse construction,hence bringing for the audience a new research insight for appreciating and interpreting commencement speeches as one kind of educational discourses.Meanwhile,this study is hopefully to provide significant implications and inspiration for foreign language teaching and learning.A good understanding and application of conceptual metaphors can not only promote reading comprehension of discourses,but also improve the effects of cross-cultural communication.