Abstract Reflection about the relationship between language and body has a long history. In spite of the fact that for centuries the most audacious thinkers and philosophers have established a close link between brain and speech, it is the merit of the century of enlightenment to have examined the problem of these relationships. To accept the fact that language was a product of the physical nature of humans, it was necessary to demonstrate that language abilities could originate from our activities and not from a gift of God and to explain that language was in fact the product of human social life. This article shows the most significant steps of these efforts by the thinkers of the eighteenth century to reevaluate in a more realistic way the whole problem of language's origin and of the physical conditions that determine the acquisition of speech by humankind. Meanwhile, new theories about the brain and the nervous system give some support to those who definitely wish to see language merely as a human product.