This universalising step, which Singer traces from Kant to Hare,[14] is crucial and sets him apart from those moral theorists, from Hobbes to David Gauthier, who tie morality to prudence. Universalisation leads directly to utilitarianism, Singer argues, on the strength of the thought that one's own interests cannot count for more than the interests of others. Taking these into account, one must weigh them up and adopt the course of action that is most likely to maximise the interests of those affected; utilitarianism has been arrived at. Singer's universalising step applies to interests without reference to who has them, whereas a Kantian's applies to the judgments of rational agents (in Kant's kingdom of ends, or Rawls's Original Position, etc.). Singer regards Kantian universalisation as unjust to animals.