The Euroscepticism that led to the result of the Brexit referendum is not new, but can actually be traced back hundreds of years. This article explores Euroscepticism by comparing the modern EU with the European federation that was proposed in the 18th century by the Abbé de Saint-Pierre. The ‘peace project’ that he outlined generated many objections from philosophers including Rousseau, Kant and Voltaire. Although these objections were aimed at an abstract political proposal this article shows that similar arguments are in fact made today by contemporary Eurosceptics against an existent political institution – the EU. Whilst acknowledging that the federation proposed by Saint-Pierre and the structure of the modern EU differ greatly, this article highlights how they share one important aim, namely the maintenance of peace in Europe - an aim that makes their comparison so fruitful but one which was largely ignored by activists during the Brexit referendum campaign.