“Human beings, having, above all creatures, received the power of reason… need to be aware where nature is unaware. Nature reaches its culmination in humans, but human consciousness has not its essence in itself or nature.”

Preface, A vii
Critique of Pure Reason (1781; 1787)

Of Atheism
Essays (1625)

The Origin of Humankind (1994)

2000s, The Central Idea (2006)
Context: The equality of mankind is best understood in light of a two-fold inequality. The first is the inequality of mankind and of the subhuman classes of living beings that comprise the order of nature. Dogs and horses, for example, are naturally subservient to human beings. But no human being is naturally subservient to another human being. No human being has a right to rule another without the other's consent. The second is the inequality of man and God. As God's creatures, we owe unconditional obedience to His will. By that very fact however we do not owe such obedience to anyone else. Legitimate political authority—the right of one human being to require obedience of another human being—arises only from consent. The fundamental act of consent is, as the 1780 Massachusetts Bill of Rights states, "a social compact by which the whole people covenants with each citizen and each citizen with the whole people that all shall be governed by certain laws for the common good." The "certain laws for the common good" have no other purpose but to preserve and protect the rights that each citizen possesses prior to government, rights with which he or she has been "endowed by their Creator." The rights that governments exist to secure are not the gift of government. They originate in God.

Source: Household Papers and Stories (1864), Ch. 6.

Anarchism and Other Essays (1910), The Traffic in Women

Vol. I, Ch. 10, as translated by R. B. Haldane
Variant translations:
Reason is feminine in nature; it can give only after it has received. Of itself alone, it has nothing but the empty forms of its operation.
As translated by Eric F. J. Payne (1958) Vol. II, p. 50
Reason is feminine in nature: it will give only after it has received.
The World as Will and Representation (1819; 1844; 1859)
Context: Reason is feminine in nature; it can only give after it has received. Of itself it has nothing but the empty forms of its operation. There is no absolutely pure rational knowledge except the four principles to which I have attributed metalogical truth; the principles of identity, contradiction, excluded middle, and sufficient reason of knowledge. For even the rest of logic is not absolutely pure rational knowledge. It presupposes the relations and the combinations of the spheres of concepts. But concepts in general only exist after experience of ideas of perception, and as their whole nature consists in their relation to these, it is clear that they presuppose them.

As quoted in Expressionism (2004) by Norbert Wolf and Uta Grosenick, p. 64

Source: Cristina Lizardo: “It’s time to show what is being done to damage the image of the PLD.” https://www.catholictranscript.org/cristina-lizardo-its-time-to-show-what-is-being-done-to-damage-the-image-of-the-pld/ (27 June 2021)