Born into the desolation of a working-class family, Lacasse's artistic vocation was first outlined at the local stone quarries where he worked as a young teenager. During 1910-12, Lacasse intuitively established his search for light, extracted from the glistening rock. In 1925, Lacasse moved to Paris where he became known as a painter of religious scenes. However, with Brancusi as his neighbour, Lacasse was inspired to revisit his teenage interest in light and the composition of stone fragments. This led him to make a series of small abstract paintings during the 1930s. His acquaintance with Robert Delaunay influenced his coloristic development. Upon his return to Paris in 1946, after having spent the war years in Britain, Lacasse had been overshadowed by Serge Poliakoff, who admitted to having learnt much from Lacasse during the late 1930s during his visits to Lacasse's Montparnasse gallery 'l'Equipe'.

Lacasse's oeuvre is testimony to his search for the ultimate metaphysical light, inspired by his reading of Thomas Aquinas' 'Beatudes'.