“If you ask three philosophers how social constructs work, you'll get four theories.”

Origin unknown. Attributed to Sydney Smith in Speaker's Handbook of Epigrams and Witticisms (1955) by Herbert Prochnow, p. 190. Variant reported in Why Are You Single? (1949) by Hilda Holland, p. 49: «When asked by a young man whether to marry, Socrates is said to have replied: "By all means, marry. If you will get for yourself a good wife, you will be happy forever after; and if by chance you will get a common scold like my Xanthippe—why then you will become a philosopher."»
Misattributed
Variant: By all means, marry. If you get a good wife, you'll become happy; if you get a bad one, you'll become a philosopher.

Source: My Little Chickadee (1940)

Anarchism or Socialism (1906)

Source: The Laundry Files, The Annihilation Score (2015), Chapter 7, “Officer Friendly” (p. 113)

Sir Douglas Robb Lectures, University of Auckland (1979); lecture 1, "Photons: Corpuscles of Light" https://www.youtube.com/watch?v=eLQ2atfqk2c&t=24m2s
Context: There's a kind of saying that you don't understand its meaning, 'I don't believe it. It's too crazy. I'm not going to accept it.'… You'll have to accept it. It's the way nature works. If you want to know how nature works, we looked at it, carefully. Looking at it, that's the way it looks. You don't like it? Go somewhere else, to another universe where the rules are simpler, philosophically more pleasing, more psychologically easy. I can't help it, okay? If I'm going to tell you honestly what the world looks like to the human beings who have struggled as hard as they can to understand it, I can only tell you what it looks like.

Preface.
A History of Science Vol.1 Ancient Science Through the Golden Age of Greece (1952)
Context: The history of science should not be an instrument to defend any kind of social or philosophic theory; it should be used only for its own purpose, to illustrate impartially the working of reason against unreason, the gradual unfolding of truth, in all its forms, whether pleasant or unpleasant, useful of useless, welcome or unwelcome.