Perthshire native James Croll (1821-1890) was born into impoverished circumstances and his scientific achievements were accomplished in spite of poverty, a lack of formal schooling and in the face of chronic ill health. Croll, who achieved significant recognition in scientific circles as a Fellow of the Royal Society, is now almost exclusively remembered for his pioneering work on climate variability based on changes in the Earth’s orbit. Metaphysics was his ‘favourite study’ and ‘first love’.