The article discusses how Lionel Robbins' definition of economics laid the groundwork for focusing on individual choice in the field. It suggests that Robbins' methodological individualism approach views the isolated individual as a starting point to understand more complex social phenomena in economics. The study introduces the concept of 'first-step individualism' to categorize Robbins' approach, highlighting that his rationale was not to reduce social phenomena to individual behavior but to provide a foundation for analyzing more intricate economic issues in the future.