The first of Vico's contributions to historical method, the first source for the knowledge of the earliest civilisations which he exposed, is the etymology of language. The usual methods of this study in his time were purely arbitrary: it proceeded by considering the sound of each syllable or letter and looking for other superficial resemblances, and inferring from these facts the derivation of a word from this or that language, Latin, Greek or Hebrew. But etymology becomes a fruitful study only when it is remembered that language is the best evidence for the ancient life of a people, the life lived by them while the language was in the making: and when the student accordingly never ceases to explain language by customs and customs by language. Thus the etymology of abstract words leads us into the heart of a purely rustic society; for _intellegere,_ to understand, for example, recalls _legere,_ to collect the produce of the fields (hence _legumina,_ vegetables); _disserere,_ to discuss, refers to scattering seed; and the majority of words for inanimate things reveal relations with the human body and its members, and the sensations and passions of man; thus "mouth" means any aperture, "lip" the edge of a pot, "forehead" and "back" are used for before and behind; and so on. Vico aimed at one science of etymology common to all native languages, composed of monosyllabic, and largely onomatopoeic roots: another of foreign loan-words, introduced after nations became mutually acquainted: a third, of universal application, for the science of international law, from which it should appear how the same men, facts or objects, looked at from the different points of view of different nations, received different names; and finally a dictionary of mental words, common to all nations, which should explain the uniform ideas of substances and the different modifications of them in national thought concerning the human needs and utilities common to all, according to the differences of their situation, climate, character and customs, and should thus narrate the origins of the various vocal languages, all converging in an ideal common language.