An examination of the historical background of the two languages. This book grew out of a great concern regarding the question of the influence of the Greek language on English. As many British lexicographers quite often point out, the full understanding of the English language and its development through the ages requires a deep knowledge of its Greek roots. The book identifies the reasons why so many Western European languages (where English also belongs) resort to the Greek glossary to express feelings, concepts, ideas or to name objects. My intuition is that the Greek language, more than Latin, is suitable and ideal for the creation of new words; Latin, though very flexible, has difficulties in the production of compound words - to include two different meanings in one single word. Science constantly discovers new objects and concepts; a name must be given to them. The Greek thesaurus is the solution. It is resolved, at this point, to direct the progress of this book into two sections: 1. a historical section, which will illuminate the various stages of development of the two languages from the beginning of their formation up to now. 2. the second section will focus on a detailed presentation of the Greek influence on English, concentrating on the areas of (1) Psychology and (2) Philosophy. But such an investigation will yield, by contrast, valuable insights relevant to the English influence on Greek. It is a well-known linguistic fact that language contact always results in interference phenomena. It would be unfair for the English language if we claimed that it only received but it did not give. The gradually increasing influence of English as an international and widely spoken language upon Greek will therefore be examined in the respective chapter of the main analysis.