The idea that language sets the boundaries for thought probably came into western thought from Indian writings of the 6th century (Bhartrihari, 450-510). It led, via von Humboldt (1767-1835), and others, to the famous so-called ‘Sapir-Whorf hypothesis’, or concept of ‘linguistic relativity’ (Whorf, 1956). This argues that the grammatical categories of a given language have a guiding influence over the way its users understand the world, and therefore behave in it.