Karl Kraus quote: “To be human is erroneous.”

“Not until the courageous have become smart and the smart courageous, can we feel what often has been erroneously declared: an advancement of human kind.”

Erich Kästner (1899–1974) German children's writer

“It is common to assume that human progress affects everyone-that even the dullest man, in these bright days, knows more than any man of, say, the Eighteenth Century, and is, far more civilized. This assumption is quite erroneous.”

H.L. Mencken (1880–1956) American journalist and writer

Homo Neanderthalensis Baltimore Sun (June 29th, 1925), The Impossible Mencken
1920s
Context: Such obscenities as the forthcoming trial of the Tennessee evolutionist, if they serve no other purpose, at least call attention dramatically to the fact that enlightenment, among mankind, is very narrowly dispersed. It is common to assume that human progress affects everyone-that even the dullest man, in these bright days, knows more than any man of, say, the Eighteenth Century, and is, far more civilized. This assumption is quite erroneous. The man of the educated minority, no doubt, know more than their predecessors, and of some of them, perhaps, it may be said that they are more civilized- though I should not like to be put to giving names0 but the great masses of men, even in this inspired republic, are ignorant, they are dishonest, they are cowardly, they are ignoble. They know little if anything that is worth knowing, and there is not the slightest sign of a natural desire among them to increase their knowledge.

“Creation exists for its Creator. Years of anthropocentrism have almost completely obscured this simple but fundamental point. What follows from this is that animals should not be seen simply as means to human ends. The key to grasping this theology is the abandoning of the common but deeply erroneous view that animals exist in a wholly instrumental relationship to human beings.”

Andrew Linzey (1952) British theologian and divine

Source: Animal Theology (1994), p. 24

“Every result of human purposiveness is of indisputable importance for man's social existence, but we should stop regarding social processes as deterministic manifestations of a necessary course of events. Such a view can only lead to the most erroneous conclusions and contribute to a fatal confusion in our understanding of historical events.”

Rudolf Rocker book Nationalism and Culture

Source: Nationalism and Culture (1937), Ch. 1 "The Insufficiency of Economic Materialism"
Context: Every process which arises from our physical being and is related to it, is an event which lies outside of our volition. Every social process, however, arises from human intentions and human goal setting and occurs within the limits of our volition. Consequently, it is not subject to the concept of natural necessity. … We are here stating no prejudiced opinion, but merely an established fact. Every result of human purposiveness is of indisputable importance for man's social existence, but we should stop regarding social processes as deterministic manifestations of a necessary course of events. Such a view can only lead to the most erroneous conclusions and contribute to a fatal confusion in our understanding of historical events.
It is doubtless the task of the historian to trace the inner connection of historical events and to make clear their causes and effects, but he must not forget that these connections are of a sort quite different from those of natural physical events and must therefore have quite a different valuation.

“I am not so enamored of my own opinions that I disregard what others may think of them. I am aware that a philosopher's ideas are not subject to the judgment of ordinary persons, because it is his endeavor to seek the truth in all things, to the extent permitted to human reason by God. Yet I hold that completely erroneous views should be shunned.”
Neque enim ita mihi mea placent, ut non perpendam, quid alii de illis iudicaturi sint. Et quamvis sciam, hominis philosophi cogitationes esse remotas à iudicio vulgi, propterea quòd illius studium sit veritatem omnibus in rebus, quatenus id à Deo rationi humanæ permissum est, inquirere, tamen alienas prorsus à rectitudine opiniones fugiendas censeo. Itaque cum mecum ipse cogitarem, quàm absurdum ἀκρόαμα existimaturi essent illi, qui multorum seculorum iudiciis hanc opinionem confirmatam norunt, quòd terra immobilis in medio cœli, tanquam centrum illius posita sit, si ego contra assererem terram moveri...

Nicolaus Copernicus book De revolutionibus orbium coelestium

Preface
De revolutionibus orbium coelestium (1543)
Context: For I am not so enamored of my own opinions that I disregard what others may think of them. I am aware that a philosopher's ideas are not subject to the judgment of ordinary persons, because it is his endeavor to seek the truth in all things, to the extent permitted to human reason by God. Yet I hold that completely erroneous views should be shunned. Those who know that the consensus of many centuries has sanctioned the conception that the earth remains at rest in the middle of the heaven as its center would, I reflected, regard it as an insane pronouncement if I made the opposite assertion that the earth moves.

“How can I accept a doctrine which sets up as its bible, above and beyond criticism, an obsolete economic textbook which I know to be not only scientifically erroneous but without interest or application for the modern world? How can I adopt a creed which, preferring the mud to the fish, exalts the boorish proletariat above the bourgeois and the intelligentsia who, with whatever faults, are the quality in life and surely carry the seeds of all human advancement?”

John Maynard Keynes book Essays in Persuasion

"A Short View of Russia" (1925); Originally three essays for the Nation and Athenaeum, later published separately as A Short View of Russia (1925), then edited down for publication in Essays in Persuasion (1931)
Ref: en.wikiquote.org - John Maynard Keynes / Quotes / Essays in Persuasion (1931)
Essays in Persuasion (1931), A Short View of Russia (1925)