One work by this thinker 
One work by this thinker argues that unconditional prophecies in fixed systems arise from existential statements and conditional predictions. That work was continued in Conjectures and Refutations and argues against both the naturalistic and anti-naturalistic forms of the title theory. Another work by this thinker asserts that induction is against common sense and submits that no scientific theory can be proven beyond all doubt. This man decried (*) Utopian efforts for relying too heavily on social experiments in a work that declares a philosopher to be totalitarian in its first chapter, "The Spell of Plato." For 10 points, name this German philosopher who formulated falsifiability and wrote The Poverty of Historicism and The Open Society and its Enemies.
One work by this thinker argues that unconditional prophecies in fixed systems arise from existential statements and conditional predictions.
Karl {Popper} [or Sir Karl Raimund {Popper}]