“It is a strange fact that freedom and equality, the two basic ideas of democracy, are to some extent contradictory.”

Source: On Representative Government (1861), Ch. VII: Of True and False Democracy; Representation of All, and Representation of the Majority only (p. 247)

As quoted in "Some Szilardisms on War, Fame, Peace", LIFE‎ magazine, Vol. 51, no. 9 (1 September 1961), p. 79
The Voice of the Dolphins : And Other Stories (1961)
Variant: I'm all in favor of the democratic principle that one idiot is as good as one genius, but I draw the line when someone takes the next step and concludes that two idiots are better than one genius.

Written speech fragment presented by to the Chicago Veterans Druggist's Association in 1906 by Judge James B. Bradwell, who claimed to have received it from Mary Todd Lincoln. Collected Works, 2:532 http://quod.lib.umich.edu/cgi/t/text/text-idx?c=lincoln;cc=lincoln;view=text;idno=lincoln2;rgn=div1;node=lincoln2%3A547
Posthumous attributions

On the Correct Handling of Contradictions Among the People
Original: (zh-CN) 民主自由都是相对的，不是绝对的，都是在历史上发生和发展的。在人民内部，民主是对集中而言，自由是对纪律而言。这些都是一个统一体的两个矛盾着的侧面，它们是矛盾的，又是统一的，我们不应当片面地强调某一个侧面而否定另一个侧面。在人民内部，不可以没有自由，也不可以没有纪律；不可以没有民主，也不可以没有集中。这种民主和集中的统一，自由和纪律的统一，就是我们的民主集中制。在这个制度下，人民享受着广泛的民主和自由；同时又必须用社会主义的纪律约束自己。这些道理，广大人民群众是懂得的。

A falsified quote invented during the 2010 financial crisis. http://www.perseus.tufts.edu/hopper/text?doc=Isoc.+7+20&fromdoc=Perseus%3Atext%3A1999.01.0144 Isocrates' actual, more nuanced, quote runs as follows:
Those who directed the state in the time of Solon and Cleisthenes did not establish a polity which … trained the citizens in such fashion that they looked upon insolence as democracy, lawlessness as liberty, impudence of speech as equality, and licence to do what they pleased as happiness, but rather a polity which detested and punished such men and by so doing made all the citizens better and wiser.
Areopagiticus, 7.20 (Norlin)
Misattributed

Section 1 : Give Responsibility to Vitally Necessary Work!
Variant translation: Work democracy introduces into liberal thinking a decisive new insight: the working masses who carry the burden of social existence are not conscious of their social responsibility. Nor are they — as the result of thousands of years of suppression of rational thinking, of the natural love function and of the scientific comprehension of living functioning — capable of the responsibility for their own freedom. Another insight contributed by work democracy is the finding that politics is in itself and of necessity unscientific: it is an expression of human helplessness, impoverishment and suppression.
The Mass Psychology of Fascism (1933), Ch. 10 : Work Democracy
Context: Work-democracy adds a decisive piece of knowledge to the scope of ideas related to freedom. The masses of people who work and bear the burden of social existence on their shoulders neither are conscious of their social responsibility nor are they capable of assuming the responsibility for their own freedom. This is the result of the century-long suppression of rational thinking, the natural functions of love, and scientific comprehension of the living. Everything related to the emotional plague in social life can be traced back to this incapacity and lack of consciousness. It is work-democracy's contention that, by its very nature, politics is and has to be unscientific, i. e., that it is an expression of human helplessness, poverty, and suppression.

In a letter to Mrs. Eleanor Roosevelt, February 10, 1944; as quoted in Voicing our visions, -Writings by women artists; ed. Mara R. Witzling, Universe New York, 1991, pp. 227-28
1930 - 1950

12 September 1848, "Discours prononcé à l'assemblée constituante le 12 Septembre 1848 sur la question du droit au travail", Oeuvres complètes, vol. IX, p. 546 https://fr.wikisource.org/wiki/Page:Tocqueville_-_%C5%92uvres_compl%C3%A8tes,_%C3%A9dition_1866,_volume_9.djvu/564; Translation (from Hayek, The Road to Serfdom):
Original text:
La démocratie étend la sphère de l'indépendance individuelle, le socialisme la resserre. La démocratie donne toute sa valeur possible à chaque homme, le socialisme fait de chaque homme un agent, un instrument, un chiffre. La démocratie et le socialisme ne se tiennent que par un mot, l'égalité; mais remarquez la différence : la démocratie veut l'égalité dans la liberté, et le socialisme veut l'égalité dans la gêne et dans la servitude.
1840s

From the Quit India speech in Bombay, on the eve of the Quit India movement (8 August 1942)
1940s
Context: Ours is not a drive for power, but purely a non-violent fight for India’s independence. In a violent struggle, a successful general has been often known to effect a military coup and to set up a dictatorship. But under the Congress scheme of things, essentially non-violent as it is, there can be no room for dictatorship. A non-violent soldier of freedom will covet nothing for himself, he fights only for the freedom of his country.
I read Carlyle’s French Revolution while I was in prison, and Pandit Jawaharlal has told me something about the Russian revolution. But it is my conviction that inasmuch as these struggles were fought with the weapon of violence they failed to realize the democratic ideal. In the democracy which I have envisaged, a democracy established by non-violence, there will be equal freedom for all. Everybody will be his own master. It is to join a struggle for such democracy that I invite you today. Once you realize this you will forget the differences between the Hindus and Muslims, and think of yourselves as Indians only, engaged in the common struggle for independence.
We cannot evoke the true spirit of sacrifice and valour, so long as we are not free. I know the British Government will not be able to withhold freedom from us, when we have made enough self-sacrifice. We must, therefore, purge ourselves of hatred.