This philosopher proposed distinguishing the existential and logical components of a statement as the second, or "semi-formal", step of his four-step process of deduction. A work by him argues for strategies of social improvement that seek to combat urgent evils rather than 
This philosopher proposed distinguishing the existential and logical components of a statement as the second, or "semi-formal", step of his four-step process of deduction. A work by him argues for strategies of social improvement that seek to combat urgent evils rather than trying to create a Utopian good; he called this "piecemeal engineering". This philosopher claimed that Platonic ideas were sympathetic with (*) totalitarianism in a book that attacks Marx and Hegel in its second volume, "The High Tide of Prophecy". Like Imre Lakatos, this philosopher distinguished science from non-science with the criterion of falsifiability. For 10 points, name this author of The Open Society and its Enemies and The Logic of Scientific Discovery.
This philosopher proposed distinguishing the existential and logical components of a statement as the second, or "semi-formal", step of his four-step process of deduction.
Karl Popper [or Karl Raimund Popper]