Quotes: Logic

A collection of quotes on various topics. The sentence in bold face is a plain statement of the quote that follows.

Logic
Contradictions can’t exist in logic, but they exist in feelings.
Logic 60 …only in logic are contradictions unable to coexist; in feelings they quite happily continue alongside each other…. Irving Stone, The Passions of the Mind (Life of Freud).

Minorities that secede will produce multiple minorities that secede from them.
Logic 37 Lincoln: If a minority, in such case, will secede rather than acquiesce, they make a precedent which, in turn, will divide and ruin them: for a minority of their own will secede from them, whenever a majority refuses to be controlled by such a minority. Sandburg, Abraham Lincoln: The War Years.

If they are consistent, the Southern states will secede from each other whenever they disagree.
Logic 99 Lincoln: To be consistent they [the Southern states] must secede from one another, whenever they shall find it the easiest way of settling their debts, or effecting any other selfish, or unjust object. Sandburg, Abraham Lincoln: The War Years.

Our generals say when they lose that they were outnumbered from three to five to one, so, since we have 400,000 men in the field, the enemy must have 1,200,000 men.
Logic 213 Yes Sir, went on the President [the enemy troops number] 1,200,000—no doubt of it…all our generals, when they get whipped, say the enemy outnumbers them from three to five to one…we have 400,000 men in the field, and three times four makes twelve. Sandburg, Abraham Lincoln: The War Years.

Logic is a science because it can be reduced to a set of rules like physics and geometry.
Logic 58 [Logic] is a science because to a considerable extent the processes of correct thinking can be reduced to rules like physics and geometry…. Will Durant, The Story of Philosophy, Aristotle.

Syllogism defined.
Logic 61 A syllogism is a trio of propositions of which the third (the conclusion) follows from the conceded truth of the other two. Will Durant, The Story of Philosophy, Aristotle.

Syllogisms don’t produce truth, but clarify it.
Logic 61 …the syllogism is not a mechanism for the discovery of truth so much as for the clarification of exposition and thought. Will Durant, The Story of Philosophy, Aristotle.

The people who justify slavery as good should want to become slaves themselves.
Logic 195 Lincoln: “Although volume upon volume is written to prove slavery a very good thing, we never hear of the man who wishes to take the good of it, by being a slave himself.” Sandburg, Abraham Lincoln: The Prairie Years

If the person of lighter color can enslave the darker, you are at the mercy of anyone whose skin is fairer than your own.
Logic 197 Lincoln: It is color, then; the lighter having the right to enslave the darker…by this rule, you are slave to the first man you meet, with a fairer skin than your own. Sandburg, Abraham Lincoln: The Prairie Years

If whites are intellectually superior to the blacks, giving them the right to enslave blacks, you should be enslaved by the person who is intellectually superior to you. Logic 197 Lincoln: You mean the whites are intellectually the superiors of the blacks and therefore have the right to enslave them…by this rule, you are to be slave to the first man you meet with an intellect superior to your own. Sandburg, Abraham Lincoln: The Prairie Years

If you do not object to my taking my hog to Nebraska, then I should not object to your taking your slave to Nebraska—logical if there is no difference between hogs and people.
Logic 203 Lincoln: “Inasmuch as you do not object to my taking my hog to Nebraska, therefore I must not object to you taking your slave…perfectly logical, if there is no difference between hogs and Negroes.” Sandburg, Abraham Lincoln: The Prairie Years

If the safeguards of liberty are taken from Negroes, how long will it be before the safeguards of liberty are taken from poor white men?
Logic 208 Lincoln: “And if the safeguards of liberty are broken down…when they have made things of all the free Negroes, how long, think you, before they will begin to make things of poor white men?” Sandburg, Abraham Lincoln: The Prairie Years

If I had taken up arms in behalf of the rich, powerful and intelligent, instead of Negro slaves, I would be rewarded, not punished, by this court.
Logic 264 John Brown: “Had I taken up arms on behalf of the rich, the powerful, the intelligent…every man in this court would have deemed it an act worthy of reward rather than of punishment.” Sandburg, Abraham Lincoln: The Prairie Years.