Every tradition that has thought seriously about wealth has concluded that giving is not optional — that to hold more than you need while others lack what they require is a form of injustice, not merely an absence of generosity. The mechanisms differ — tithe, zakat, dana, ubuntu — but the underlying claim is consistent: what you have is not entirely yours, and the portion that belongs to others demands accounting. Reason reaches this conclusion independently.
Each step builds on the last.