“We are all inventors, each sailing out on a voyage of discovery, guided each by a private chart, of which there is no duplicate. The world is all gates, all opportunities.”

Grundrisse (1857-1858)
Source: Notebook I, The Chapter on Money, p. 76.

Source: The Pocket Manager, (1987), p. 73

Source: Middlemarch

"A Satyr upon the Follies of the Men of the Age", line 109; cited from The Works of His Grace, George Villiers, the Duke of Buckingham (London: T. Evans, 1770) vol. 2, p. 156

Le seul véritable voyage, le seul bain de Jouvence, ce ne serait pas d'aller vers de nouveaux paysages, mais d'avoir d'autres yeux, de voir l'univers avec les yeux d'un autre, de cent autres, de voir les cent univers que chacun d'eux voit, que chacun d'eux est.
Source: In Search of Lost Time, Remembrance of Things Past (1913-1927), Vol. V: The Captive (1923), Ch. II: "The Verdurins Quarrel with M. de Charlus"

Cardanus Comforte (1574)

At Chateau Laurier, Ottawa, Canada, November 9, 1954 ; as cited at The Churchill Centre http://www.winstonchurchill.org/learn/speeches/quotations/famous-quotations-and-stories.
Post-war years (1945–1955)

A Vindication of Natural Society (1756)
Context: I need not excuse myself to your Lordship, nor, I think, to any honest man, for the zeal I have shown in this cause; for it is an honest zeal, and in a good cause. I have defended natural religion against a confederacy of atheists and divines. I now plead for natural society against politicians, and for natural reason against all three. When the world is in a fitter temper than it is at present to hear truth, or when I shall be more indifferent about its temper, my thoughts may become more public. In the mean time, let them repose in my own bosom, and in the bosoms of such men as are fit to be initiated in the sober mysteries of truth and reason. My antagonists have already done as much as I could desire. Parties in religion and politics make sufficient discoveries concerning each other, to give a sober man a proper caution against them all. The monarchic, and aristocratical, and popular partisans have been jointly laying their axes to the root of all government, and have in their turns proved each other absurd and inconvenient. In vain you tell me that artificial government is good, but that I fall out only with the abuse. The thing! the thing itself is the abuse! Observe, my Lord, I pray you, that grand error upon which all artificial legislative power is founded. It was observed that men had ungovernable passions, which made it necessary to guard against the violence they might offer to each other. They appointed governors over them for this reason! But a worse and more perplexing difficulty arises, how to be defended against the governors? Quis custodiet ipsos custodes? In vain they change from a single person to a few. These few have the passions of the one; and they unite to strengthen themselves, and to secure the gratification of their lawless passions at the expense of the general good. In vain do we fly to the many. The case is worse; their passions are less under the government of reason, they are augmented by the contagion, and defended against all attacks by their multitude.