I have spent a lot of time worrying over Hume’s statement, “Tis perfectly rational to prefer the destruction of the world to the scratching of one’s finger.” In fact it is not rational at all. As soon as the scratch is over one realizes that it is laughable to think the scratch on the finger logically implies the destruction of the world.
Hume opens his Treatise on Human Nature with the statement, “All the perceptions of the human mind resolve themselves into two distinct kinds, which I shall call Impressions and Ideas.” I have always thought this a silly statement; it is gratifying to realize the statement about being reasonable to prefer the destruction of the world to a scratch on the finger is equally silly.
Of course Hume could not have been aware of the scientific approach to philosophical questions we now have, though he ought to have been better aware of what Copernicus, Galileo, and Newton had achieved. Locke, at least, was aware of these achievements In his struggle to understand the relation between “primary” and “secondary” qualities.