This article explores the educational philosophy of Asja Lacis' proletarian children's theatre. Taking her post-First World War encounter with Russian street children as a starting point for my inquiry, I argue that Lacis regards the theatre as a rehearsal space for life. Here, children are to be absorbed into the craft of theatre, with the aim of honing their moral and aesthetic sense as a (self-guided) reorientation of their attention and desire towards (the possibilities of) the Good. Demarcating a porous educational theatre space that provides practical artistic opportunities for this education of attention, Lacis hopes to structure children's aesthetic, social, material and sensory engagement with their surroundings, whilst also ensuring their individual freedom as moral agents. Respecting children's ways of engaging in the world, Lacis posits theatrical improvisation as the key activity. Here, children create their own stories and metaphors about how life might be lived, thereby practising attention to, 'testing' and reflecting upon, the (possible) Good Life. The educator's pedagogical gesture is hereby that of observation: She pays attention to the social--artistic tensions that occur, as potential heralds of the child's unique way of embodying (and conceptualising) the Good Life. Theatre is here understood as a (negative) dialectical site of education, one that acknowledges the dark and uncertain relation between the child's commitment to the Good, and its (uncertain) coming into being in daily life. The student-teacher relationship can indeed become a pedagogical conduit for this search for (and embodiment of) wisdom, but cannot provide a blueprint as to how the journey might be conducted, or predict how the Good will manifest. It is in the 'loving' non-action of the educator, who honours the unpredictability of the arrival of virtue, and the unexpected form that it might take, that children's theatre is considered 'truly revolutionary': becoming a witness to Eros's (strange) presence in the child's unique gesture as a result.