Excited by the scientific breakthroughs of the day, David Hume set out to construct a science of the mind. 1748's An Enquiry Concerning Human Understanding is the result. A work that had a huge influence on great thinkers, including Kant, An Enquiry is Hume's examination of how we obtain information and form beliefs. He argues that we gain knowledge empirically, through our senses. But while these impressions are key to our beliefs about the world, Hume felt that we underestimate the importance of fact and reason. An Enquiry is now considered one of the greatest works of Western philosophy, and Hume one of its key thinkers.