This study rehabilitates Marina Tsvetaeva (1892-1941) as a serious, innovative ethical thinker who developed an ethics for the poet that could dispense with universal value guarantees. For Tsvetaeva, ethical judgements had to be individual rather than universal, open to revision rather than permanent. Examining her ideational background, the study sheds new light on the pre-exile years, when she suffered from a profound uncertainty about the moral nature and duty of the poet. It identifies the experience of exile as a catalyst for the development of her ethical thought. Considering Tsvetaeva's application of her ethics in her life, this study reveals her emphasis on the personal to be the direct result of her ethical belief in individual judgements. Her conscious effort to counteract dominant political ideologies similarly stems from her ethical suspicion of any kind of claim on universal truth. Finally the study assesses the significance of Tsvetaeva's suicide, after her return to the Soviet Union, revealing it to be the inevitable, terrifying consequence of her ethical self-definition, her commitment to individual freedom, and the pursuit of higher truths.