I have picked up Peter Watson's The Modern Mind published in 2000, as a step towards coming up with canonical text lists for the 20th century (at least through ~1945). I have finished Part One: From Freud to Wittgenstein which covers 20th century intellectual history up till WWI. In reading these 168 pages, I took note of works that are 1) within the scope covered here - at least philosophy and literature (no history works or religious texts have been mentioned yet), plus the new "social sciences" like psychology, sociology, anthropology, achaeology etc. 2) Authors / works that is somewhat famous (at least ones I have at least heard of before in some other context); and 3) works that are mentioned in the texts as of more importance. In the list below, I am excluding math & science works, thus I am excluding Russell's / Whitehead's Principia Mathematica; also excluded are art criticism / theory / manifesto. If multiple works by a single author is mentioned, I bold the more important works.
1. Signmund Freud: Interpretation of Dreams (1900); Totem and Taboo (1913)
2. Edmund Husserl: Logical Investigations Vol 1 & 2 (1901)
3. Max Weber: The Protestant Ethic and the Spirit of Capitalism (1904)
4. Joseph Conrad: Heart of Darkness (1902)
5. Henri Bergson: Creative Evolution (1907)
6. William James: Varieties of Religious Experience (1902); Pragmatism (1907)
7. W.E.B. Du Bois: Souls of Black Soul (1903)
8. Franz Boas: The Mind of Primitive Man (1910)
9. Guillaume Apollinaire: Alcools ("Liquors", 1913)
10. Carl Jung: The Psychology of the Unconscious (1913)
11. Thomas Mann: Buddenbrooks (1901); Death in Venice (1913)
12. D.H. Lawrence: Sons and Lovers (1913)
13. Marcel Proust: In Search of Lost Time, Volume 1: Swann's Way (1913)
14. Wilfred Owen (Poetry, especially in 1917/1918)
15. Ludwig Wittgenstein: Tractatus Logico-Philosophicus (1921 German version/ 1922 English translation; written and completed during WWI)
1. From this, one can see that Watson's account really just includes works written in English, French and German. Even within the western world, there are no Italian, Spanish, Russian, Portuguese, Polish ... So this is hardly going to be the complete list from which to pick canonical works from.
2. Now we are in 2014 - so if we keep the rule of canonization takes ~100 years, then from this list, who are truly canonical? My pick is Freud, Weber, James, Proust. Wittgenstein is already after ~1915.
a. James is the lightweight among this list of 4, but it is hard to not include any Americans for 20th century.
b. I also feel that even though Freud felt he was doing medicine, ultimately the theory of unconscious is more philosophical than scientific.
c. Weber as a founder of sociology is not as canonical as Marx - but sociology probably ends up being considered as a type of historiography or political phisophy - in either case this still falls into the genre type of my canonical text lists.
d. My personal feeling / hope is that the fetish for race - clearly important for 20th century perspectives, but I think in the long-term it may become an small blip in intellectual history (thus no Du Bois or Boas)
e. Literature-wise: Paris was still center of artistic / literary activities. While Mann is not really known much outside of those focused on Germanic development (Watson - author of a later work The German Genius - clearly has his eyes quite fixed on German). For English-language literature - it is hard for Conrad or Lawrence or Owen to compete with Joyce or T.S.Eliot. Thus the bet on Proust for the period before 1915.