Hume’s text

All sceptics pretend, that, if reason be considered in an abstract view, it furnishes invincible arguments against itself; and that we could never retain any conviction or assurance, on any subject, were not the sceptical reasonings so refined and subtile, that they are not able to counterpoise the more solid and more natural arguments derived from the senses and experience. But it is evident, whenever our arguments lose this advantage, and run wide of common life, that the most refined scepticism comes to be upon a footing with them, and is able to oppose and counterbalance them.

Amended text

All sceptics claim that if reason is considered abstractly, it provides invincible arguments against itself, and that we could never retain any opinion or confidence on any subject if it were not that the sceptical reasonings ·in which reason discredits itself· are so refined and subtle that they cannot outweigh the more solid and more natural arguments derived from the senses and experience. But it is obvious that when our arguments lose this advantage ·of solidity and naturalness·, and run wide of everyday life, the most refined scepticism comes to be on an equal footing with them and can oppose and counterbalance them.