“The free exploring mind of the individual human is the most valuable thing in the world.”

Source: Tomorrow Is Now (1963), p. 71

Out of Control: The New Biology of Machines, Social Systems and the Economic World (1995), New Rules for the New Economy: 10 Radical Strategies for a Connected World (1999)

Fiction, The Call of Cthulhu (1926)
Context: The most merciful thing in the world, I think, is the inability of the human mind to correlate all its contents. We live on a placid island of ignorance in the midst of black seas of infinity, and it was not meant that we should voyage far. The sciences, each straining in its own direction, have hitherto harmed us little; but some day the piecing together of dissociated knowledge will open up such terrifying vistas of reality, and of our frightful position therein, that we shall either go mad from the revelation or flee from the light into the peace and safety of a new dark age.

Source: The Purpose Driven Life: What on Earth Am I Here for?

Source: Principles of Economics, (1890), p. 468 (9th ed. 2009).
Context: If we compare one country of the civilized world with another, or one part of England with another, or one trade in England with another, we find that the degradation of the working-classes varies almost uniformly with the amount of rough work done by women. The most valuable of all capital is that invested in human beings; and of that capital the most precious part is the result of the care and influence of the mother, so long as she retains her tender and unselfish instincts, and has not been hardened by the strain and stress of unfeminine work.

Source: Myatt, David. Myngath - Some Recollections of the Wyrdful Life of David Myatt, CreateSpace, 2013, ISBN 978-1484110744

Variant: Time is the most precious gift in our possession, for it is the most irrevocable.
Source: As quoted in LIFE magazine (22 April 1957), p. 152; also in Letters and Papers from Prison (1967), p. 47.
Context: Time is the most precious gift in our possession, for it is the most irrevocable. This is what makes it so disturbing to look back upon the time which we have lost. Time lost is time when we have not lived a full human life, time unenriched by experience, creative endeavor, enjoyment, and suffering. Time lost is time not filled, time left empty.

Diogenes Laërtius, Lives and Opinions of Eminent Philosophers, Book 5.

The Rights of Man, or what are we fighting for? (1940)
Context: Throughout the whole world we see variations of this same subordination of the individual to the organisation of power. Phase by phase these ill-adapted governments are becoming uncontrolled absolutisms; they are killing that free play of the individual mind which is the preservative of human efficiency and happiness. The populations under their sway, after a phase of servile discipline, are plainly doomed to relapse into disorder and violence. Everywhere war and monstrous economic exploitation break out, so that those very same increments of power and opportunity which have brought mankind within sight of an age of limitless plenty, seem likely to be lost again, it may be lost forever, in an ultimate social collapse.