 Gödel, Kurt: incompleteness theorems |  Hilbert, David: program in the foundations of mathematics |  Husserl, Edmund |  Leibniz, Gottfried Wilhelm |  mathematics, philosophy of: intuitionism |  model theory |  model theory: first-order |  phenomenology |  Platonism: in the philosophy of mathematics |  realism |  set theory |  set theory: continuum hypothesis |  set theory: large cardinals and determinacy 