Classical liberals saw utility as the foundation for public policies. This broke both with conservative "tradition" and Lockean "natural rights", which were seen as irrational. Utility, which emphasises the happiness of individuals, became the central ethical value of all liberalism. Although utilitarianism inspired wide-ranging reforms, it became primarily a justification for "laissez-faire" economics. However, classical liberals rejected Smith's belief that the "invisible hand" would lead to general benefits and embraced Malthus' view that population expansion would prevent any general benefit and Ricardo's view of the inevitability of class conflict. "Laissez-faire" was seen as the only possible economic approach and any government intervention was seen as useless and harmful. The Poor Law Amendment Act 1834 was defended on "scientific or economic principles" while the authors of the Elizabethan Poor Law of 1601 were seen as not having had the benefit of reading Malthus.