Full Idea
The 'instrumental' (Humean) sense of rationality means a capacity for generating or recognizing contingent truths, contextually normative rules, consequentialist obligations, and hypothetical 'ought' claims. Reason is 'the slave of the passions'.
Gist of Idea
Humean Instrumental rationality is the capacity to seek contingent truths
Source
Robert Hanna (Rationality and Logic [2006], Intro)
Book Reference
Hanna,Robert: 'Rationality and Logic' [MIT 2006], p.-6