Dramatis Personae


  • Stanisław Leśniewski  (1886-1939)  [sta'ɲiswaf lɛ'ɕɲɛfski] developed three logical systems in the period between the two wars, Protothetic, Ontology, and Mereology. Our purpose here is to provide information about these systems --- primarily technical infomation. 


Jan Łukasiewicz (1878–1956) was co-founder of the Warsaw School of Logic.

Boleslaw Sobocinski

  • Bolesław Sobociński (1906–1980) received his Ph.D. in 1938 under the direction of Jan Łukasiewicz (1878–1960) and then served as assistant to Leśniewski. This close contact with the two founders of the Warsaw School of Logic determined the course of his research. He played an important role in the Polish underground during WW II, escaped to Brussels where he worked for several years and then emigrated to the US. After a few years in St. Paul, MN, he joined the faculty at the University of Notre Dame. He founded the Notre Dame Journal of Formal Logic and edited it for 19 years.


In the Spring of 1964 Sobocinski taught a course dealing with Lesniewski's Ontology. Items 1 and 2 below are the first part of that course. 

While in Brussels, Sobocinski prepared three notebooks dealing with Ontology. Item 5 below is the third of them. The first two will be added later after I scan them. 


When Lesniewski pubished O podstawach matematyki (On the foundations of mathematics; briefly OPM) he was uncomfortable with formal language and so expressed these derivations in ordinary (Polish) language. Here Sobocinski has translated them into the formal language of Mereology.

Item 1 is the first development of Mereolgy, Item 2 is the second. 


Item 1 is the list of Sobocinski's papers that Rickey prepared when donating about half of his papers to the Archives at the University of Notre Dame. Item 2 is the arrangement of the papers that was prepared by the archivists. 


  1. Do any offprints of Sobocinski's paper,``Z badan nad prototetyka,'' Collectanea Logica, 1 (1939), 171--177, survive?
  2. Is there a good account in English of the cryptographic work of Lesniewski, Mazurkiewicz and Sierpinski during the Polish-Soviet war.

Files coming soon.