The objective of this thesis is to investigate examples of mythological motifs regarding their history and meaning. The thesis aims to show that the symbolic language used in myths, legends, folk and fairy tales have an important role within modern society and still have an effect on people's lives. Chapter I gives an overview of the Lady of the Lake tales contained in John Rhys' work Celtic Folklore Welsh and Manx and investigates whether those tales express in symbolic language actual historic events and issues of the times during which those tales were formulated. Chapter II widens the perspective by looking at various examples of water legends in Wales which are related to the Lady of the Lake cycle. It becomes evident that the uniting factor of all those tales is that they deal with conflicting ethical systems. Chapter III engages a detailed analysis of the motifs contained in the Legend of the "Lady of Llyn y Fan Fach" and combines the historic interpretation approach with a psychological method of interpretation. Chapters IV and V are concerned with tracing the motifs discussed in the previous chapters in twentieth-century works. Chapter IV looks at how one author uses motifs and universal symbols to make personal statements. Chapter V interprets the Walt Disney cartoon "The Little Mermaid". The Conclusion expands on the previously introduced idea of the development of the human mind. It has been suggested that symbolic language can reflect aspects of human reality and an attempt has been made to show how symbolic language operates. The Conclusion discusses the idea that the mythological way of thinking should be amalgamated with the rational capabilities of the human mind in order to create a new and effective understanding of reality.