“There is a certain class of people who prefer to say that their fathers came down in the world through their own follies rather than to boast that they rose in the world through their own industry and talents. It is the same shabby-genteel sentiment, the same vanity of birth, which makes men prefer to believe that they are degenerated angels rather than elevated apes.”

Source: The Martyrdom of Man (1872), Chapter III, "Liberty"

A speech of Aspasia, recounted by Socrates, as portrayed in the dialogue.
Menexenus
Context: p>Let every man remind their descendants that they also are soldiers who must not desert the ranks of their ancestors, or from cowardice fall behind. Even as I exhort you this day, and in all future time, whenever I meet with any of you, shall continue to remind and exhort you, O ye sons of heroes, that you strive to be the bravest of men. And I think that I ought now to repeat what your fathers desired to have said to you who are their survivors, when they went out to battle, in case anything happened to them. I will tell you what I heard them say, and what, if they had only speech, they would fain be saying, judging from what they then said. And you must imagine that you hear them saying what I now repeat to you:Sons, the event proves that your fathers were brave men; for we might have lived dishonourably, but have preferred to die honourably rather than bring you and your children into disgrace, and rather than dishonour our own fathers and forefathers; considering that life is not life to one who is a dishonour to his race, and that to such a one neither men nor Gods are friendly, either while he is on the earth or after death in the world below.Remember our words, then, and whatever is your aim let virtue be the condition of the attainment of your aim, and know that without this all possessions and pursuits are dishonourable and evil.For neither does wealth bring honour to the owner, if he be a coward; of such a one the wealth belongs to another, and not to himself. Nor does beauty and strength of body, when dwelling in a base and cowardly man, appear comely, but the reverse of comely, making the possessor more conspicuous, and manifesting forth his cowardice.And all knowledge, when separated from justice and virtue, is seen to be cunning and not wisdom; wherefore make this your first and last and constant and all-absorbing aim, to exceed, if possible, not only us but all your ancestors in virtue; and know that to excel you in virtue only brings us shame, but that to be excelled by you is a source of happiness to us.And we shall most likely be defeated, and you will most likely be victors in the contest, if you learn so to order your lives as not to abuse or waste the reputation of your ancestors, knowing that to a man who has any self-respect, nothing is more dishonourable than to be honoured, not for his own sake, but on account of the reputation of his ancestors.The honour of parents is a fair and noble treasure to their posterity, but to have the use of a treasure of wealth and honour, and to leave none to your successors, because you have neither money nor reputation of your own, is alike base and dishonourable.And if you follow our precepts you will be received by us as friends, when the hour of destiny brings you hither; but if you neglect our words and are disgraced in your lives, no one will welcome or receive you. This is the message which is to be delivered to our children.</p

New York World, 10 May 1926
Message to the American Federation of Labor appealing for help in the General Strike.

A similar remark was reportedly made by Pratchett in The Herald (4 October 2004): I'd rather be a climbing ape than a falling angel.
"I create gods all the time - now I think one might exist" (2008)
Context: Evolution was far more thrilling to me than the biblical account. Who would not rather be a rising ape than a falling angel? To my juvenile eyes Darwin was proved true every day. It doesn't take much to make us flip back into monkeys again.

Can Love Last? (New York: W. W. Norton & Company, 2002), p. 137

Source: Just a Theory: Exploring the Nature of Science (2005), Chapter 8, “Science and Religion: Scientists Just Do Science” (pp. 136-137; minor grammatical errors corrected silently)

Variant: I prefer to be true to myself, even at the hazard of incurring the ridicule of others, rather than to be false, and incur my own abhorrence.
Source: 1840s, Narrative of the Life of Frederick Douglass, An American Slave (1845), Ch. 5
Context: I look upon my departure from Colonel Lloyd's plantation as one of the most interesting events of my life. It is possible, and even quite probable, that but for the mere circumstance of being removed from that plantation to Baltimore, I should have to-day, instead of being here seated by my own table, in the enjoyment of freedom and the happiness of home, writing this Narrative, been confined in the galling chains of slavery. Going to live at Baltimore laid the foundation, and opened the gateway, to all my subsequent prosperity. I have ever regarded it as the first plain manifestation of that kind providence which has ever since attended me, and marked my life with so many favors. I regarded the selection of myself as being somewhat remarkable. There were a number of slave children that might have been sent from the plantation to Baltimore. There were those younger, those older, and those of the same age. I was chosen from among them all, and was the first, last, and only choice.
I may be deemed superstitions, and even egotistical, in regarding this event as a special interposition of divine Providence in my favor. But I should be false to the earliest sentiments of my soul, if I suppressed the opinion. I prefer to be true to myself, even at the hazard of incurring the ridicule of others, rather than to be false, and incur my own abhorrence. From my earliest recollection, I date the entertainment of a deep conviction that slavery would not always be able to hold me within its foul embrace; and in the darkest hours of my career in slavery, this living word of faith and spirit of hope departed not from me, but remained like ministering angels to cheer me through the gloom. This good spirit was from God, and to him I offer thanksgiving and praise.

NANOG mailing list http://www.mail-archive.com/nanog@merit.edu/msg24986.html (2004)
Notes: about Sender Policy Framework