David Hume is the most famous philosopher of the Scottish Enlightenment. Yet his prominence in the history of philosophy has had the unhappy effect of overshadowing some of the most insightful critics amongst his contemporaries. This book aims to restore the philosophical credentials of a remarkable set of eighteenth-century philosophers based in Aberdeen's two university colleges. In their own time, Thomas Reid, George Campbell, Alexander Gerard and James Beattie provided compelling counters to the intellectual dominance of Hume's Edinburgh. Though they are now largely neglected, all four prove to be philosophers of striking critical acumen. Their work can still cast fresh light on Hume's influential contribution to the enduring philosophical questions of morality, religion, aesthetics and politics.