Every artist engaged in the creative process finds himself in a field of tension between imitation, emulation and invention, for consciously or not he will always want to measure up to his predecessors and contemporaries. This applies both to artists wishing to locate themselves in a tradition, evidencing admiration for their predecessors, and those seeking to distance themselves from them. It is therefore a central theme in the history of art that affords a host of perspectives. The concepts of imitation, emulation and invention have occupied an important place in Eric Jan Sluijter's wide-ranging publications and lectures. For this reason the theme of these interrelated concepts was perfectly suited for a festschrift. The essays in this festschrift invite the reader to join in a rich and thought-provoking discourse. In addition to the many explicit examples of imitation and emulation, other more implicit, not immediately perceptible, forms of emulation are presented. To mention just one: did Rembrandt actively compete with Caravaggio, and if so how should this form of emulation be defined and what is its meaning? Together, the creative and insightful responses of the authors of 'Aemulatio' have produced a comprehensive overview of an essential topic in the history of Netherlandish art.