Theo Van Rysselberghe was one of the cofounders of 'Les Vingt' and played a major role in progressive art circles of around 1900. His style gradually evolved along with the development of the leading artistic trends around the turn of the century. '' is the major work of Van Rysselberghe's oeuvre. It is a group portrait of his circle of close friends admirers and art critics. Pointillism was developed from Impressionism by the French painter Georges Seurat as a new way of painting in which light is represented by dots of colour. 'The Lecture' was the culmination of the Pointillist tradition in Belgium and a leading example for the intense interaction and exchange between Paris and Brussels artists. It was also both the most ambitious work carried out by Van Rysselberghe in this technique and the last. Van Rysselberghe does not follow the strict stylisation of Seurat but sticks to a realistic representation which enables him to convey the psychology of his models in their portraits. In his application of Pointillist theory to the portrait Van Rysselberghe pushed the boundaries of NeoImpressionism.