<p>This essay explores the relationship holding between language, cognition and space by examining the notion of “ontological commitments” and focusing on Basque as the exemplar. In recent years discussions of linguistic relativity have brought to the fore the question of language-specific ontology. This topic has been addressed by Lucy (1996; 2000), and Levinson (1996), and even earlier by Whorf in the 1940s (Whorf 1995) as well as more indirectly by language typologists such as Senft (2000) and other researchers (Barton and Frank 2001; Nisbett 2003; Nisbett et al. 2001; Watson 1990). The chapter begins by introducing the key role played by “ontological commitments” in language, using Basque as the data source and, more concretely, by means of a fine-grained analysis of two Basque morphemes -en and -ki along with the schemas associated with them. Once the morphological complexity of each of the Basque examples is established, I attempt to describe the conceptual structure inherent to each classifier, following the lead of Tuggy (2003), Inglis (2003) and Palmer (2003). Methodologically, I draw on Langacker’s (2004) remarks on type, instance and nominal grounding, as well as those of Hudson (2004) and Dryer (2004) in reference to the cross-linguistic applicability of the terms “nominal grounding” and “noun phrases”. Overall, I argue for the following position: there is an aspect of spatial representation that relates directly to the differences in these ontological commitments and is conditioned by them. Finally, I propose that cognitive linguistics can profit by broadening its focus and becoming more aware of the cross-linguistic and cross-cultural research being conducted on ontological commitments.</p>