“Needs must it be hard, since it is so seldom found. How would it be possible, if salvation were ready to our hand, and could without great labour be found, that it should be by almost all men neglected? But all things excellent are as difficult as they are rare.”

Source: Modern thinkers and present problems, (1923), p. 37: Chapter 2. Benedict de Spinoza, 1632-1677

The last sentence is a quotation of Nathaniel Hawthorne
Hawthorne and His Mosses (1850)
Context: Would that all excellent books were foundlings, without father or mother, that so it might be, we could glorify them, without including their ostensible authors. Nor would any true man take exception to this; — least of all, he who writes, — "When the Artist rises high enough to achieve the Beautiful, the symbol by which he makes it perceptible to mortal senses becomes of little value in his eyes, while his spirit possesses itself in the enjoyment of the reality."

The Conquest of Bread (1907), p. 14 http://dwardmac.pitzer.edu/anarchist_archives/kropotkin/conquest/toc.html
Variant: All things for all men, since all men have need of them, since all men worked to produce them in the measure of their strength, and since it is not possible to evaluate everyone's part in the production of the world's wealth... All is for all!
This variant was probably produced by a combination of accidental as well as deliberate omission, rather than a separate translation.
Context: The means of production being the collective work of humanity, the product should be the collective property of the race. Individual appropriation is neither just nor serviceable. All belongs to all. All things are for all men, since all men have need of them, since all men have worked in the measure of their strength to produce them, and since it is not possible to evaluate every one's part in the production of the world's wealth.
All things are for all. Here is an immense stock of tools and implements; here are all those iron slaves which we call machines, which saw and plane, spin and weave for us, unmaking and remaking, working up raw matter to produce the marvels of our time. But nobody has the right to seize a single one of these machines and say, "This is mine; if you want to use it you must pay me a tax on each of your products," any more than the feudal lord of medieval times had the right to say to the peasant, "This hill, this meadow belong to me, and you must pay me a tax on every sheaf of corn you reap, on every rick you build."
All is for all! If the man and the woman bear their fair share of work, they have a right to their fair share of all that is produced by all, and that share is enough to secure them well-being. No more of such vague formulas as "The Right to work," or "To each the whole result of his labour." What we proclaim is The Right to Well-Being: Well-Being for All!

6A:6
The Mencius

Disme: the Art of Tenths, Or, Decimall Arithmetike (1608)

Source: Ethics

The Art of Persuasion
Context: It is not among extraordinary and fantastic things that excellence is to be found, of whatever kind it may be. We rise to attain it and become removed from it: it is oftenest necessary to stoop for it.

From Her Books, I Have Chosen To Stay And Fight, WAR

Original in German: Einen solchen Standpunkt fand Goethe früh in Spinoza, und er erkennet mit Freuden, wie sehr die Ansichten dieses großen Denkers den Bedürfnissen seiner Jugend gemäß gewesen. Er fand in ihm sich selber, und so konnte er sich auch an ihm auf das schönste befestigen.
Johann Peter Eckermann, Gespräche mit Goethe in den letzten Jahren seines Lebens, 1831
A - F