William of Occam

William of Ockham - Sketch labelled "frater Occham iste", from a manuscript of Ockham's Summa Logicae, 1341

William of Ockham (ca. 1285-1349) was an English theologian and Franciscan monk. Today known as the originator of Occam's razor.

Sourced

• Numquam ponenda est pluralitas sine necessitate
  • Plurality is never to be posited without necessity.
  • Quaestiones et decisiones in quattuor libros Sententiarum Petri Lombardi (ed. Lugd., 1495), i, dist. 27, qu. 2, K
  • Okham cited in: William Thorburn (1918) "The myth of Occam's razor". In: Mind 27 (1918), 345-353.

• Frustra fit per plura, quod potest fieri per pauciora.
  • It is pointless to do with more what can be done with fewer.
  • Summa Totius Logicae, i. 12, cited in: Paul Newall (2005) "Ockham's Razor" at www.galilean-library.org

Misattributed

• Entia non sunt multiplicanda praeter necessitatem.
  • Entities should not be multiplied beyond necessity.
  • Though widely cited as Occam's razor, the popular wording is not found in his extant works.