Kelso regarded the ESOP and CSOP as pragmatic proof that his revolutionary revision of classical economic theory, and the financial techniques he derived from this new perspective, were sound and workable in the economic and business world. Kelso gained that worldly knowledge from his work as a corporate and financial lawyer, and later as senior partner in the law firm he founded. He was further motivated by his conviction that lawyers had a special responsibility to maintain and improve society's institutions in the light of its democratic values. He further believed that the business corporation was society's greatest social invention and that its executives had a fiduciary responsibility in exercising its vast power.