With this commercial activity Marseilles united intellectual and scientific activity; her grammarians were among the first to revise and annotate the poems of Homer; and bold travellers from Marseilles, Euthymenes and Pytheas by name, cruised, one along the western coast of Africa beyond the Straits of Gibraltar, and the other the southern and western coasts of Europe, from the mouth of the Tanais (Don), in the Black Sea, to the latitudes and perhaps into the interior of the Baltic.  They lived, both of them, in the second half of the fourth century B.C., and they wrote each a Periplus, or tales of their travels, which have unfortunately been almost entirely lost.

But whatever may have been her intelligence and activity, a single town situated at the extremity of Gaul and peopled with foreigners could have but little influence over so vast a country and its inhabitants.  At first civilization is very hard and very slow; it requires many centuries, many great events, and many years of toil to overcome the early habits of a people, and cause them to exchange the pleasures, gross indeed, but accompanied with the idleness and freedom of barbarian life, for the toilful advantages of a regulated social condition.  By dint of foresight, perseverance, and courage, the merchants of Marseilles and her colonies crossed by two or three main lines the forests, morasses, and heaths through the savage tribes of Gauls, and there effected their exchanges, but to the right and left they penetrated but a short distance.  Even on their main lines their traces soon disappeared; and at the commercial settlements which they established here and there they were often far more occupied in self-defence than in spreading their example.  Beyond a strip of land of uneven breadth, along the Mediterranean, and save the space peopled towards the south-west by the Iberians, the country, which received its name from the former of the two, was occupied by the Gauls and the Kymrians; by the Gauls in the centre, south-east and east, in the highlands of modern France, between the Alps, the Vosges, the mountains of Auvergne and the Cevennes; by the Kymrians in the north, north-west, and west, in the lowlands, from the western boundary of the Gauls to the ocean.

Whether the Gauls and the Kymrians were originally of the same race, or at least of races closely connected; whether they were both anciently comprised under the general name of Celts; and whether the Kymrians, if they were not of the same race as the Gauls, belonged to that of the Germans, the final conquerors of the Roman empire, are questions which the learned have been a long, long while discussing without deciding.  The only facts which seem to be clear and certain are the following.

The ancients for a long while applied without distinction the name of Celts to the peoples who lived in the west and north of Europe, regardless of precise limits, language, or origin.  It was a geographical title applicable to a vast but ill-explored territory, rather than a real historical name of race or nation.  And so, in the earliest times, Gauls, Germans, Bretons, and even Iberians, appear frequently confounded under the name of Celts, peoples of Celtica.