Schelling Friedrich Wilhelm Joseph von; Schiller Johann Christoph Friedrich von; Schleiermacher Friedrich Daniel Ernst; Schlick Moritz; scholasticism; Schopenhauer Arthur; Schrodinger Erwin; scientia; scientific method; Scotus John Duns; Searle John; secondary qualities; self-deception; self-evident; Sellars Wilfrid; semantic theory of truth; semiotics; Seneca Lucius Annaeus;