It is often claimed that the encyclical Rerum Novarum of Leo XIII laid a foundation for the emergence of trades unions and was ‘the workers’ charter’. This is a myth. The origins of the encyclical and Catholic Social Teaching in the late nineteenth-century were entirely socially conservative. Rerum Novarum condemns socialism and its authors thought that the primary purpose of what the encyclical calls ‘associations’ was devotional, ‘confraternities of mutual support and religious observance’.