„A new point is determined in Euclidean Geometry exclusively in one of the three following ways:
Having given four points A, B, C, D, not all incident on the same straight line, then
(1) Whenever a point P exists which is incident both on (A, B) and on (C, D), that point is regarded as determinate.
(2) Whenever a point P exists which is incident both on the straight line (A, B) and on the circle C(D), that point is regarded as determinate.
(3) Whenever a point P exists which is incident on both the circles A(B), C(D), that point is regarded as determinate.
The cardinal points of any figure determined by a Euclidean construction are always found by means of a finite number of successive applications of some or all of these rules (1), (2) and (3). Whenever one of these rules is applied it must be shown that it does not fail to determine the point. Euclid's own treatment is sometimes defective as regards this requisite.
In order to make the practical constructions which correspond to these three Euclidean modes of determination, correponding to (1) the ruler is required, corresponding to (2) both ruler and compass, and corresponding to (3) the compass only.
…it is possible to develop Euclidean Geometry with a more restricted set of postulations. For example it can be shewn that all Euclidean constructions can be carried out by means of (3) alone…“

Quelle: Squaring the Circle (1913), pp. 7-8

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Ernest William Hobson Foto
Ernest William Hobson
britischer Mathematiker 1856 - 1933

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Hans Reichenbach Foto
Michael Collins (Irish leader) Foto
Immanuel Kant Foto
Hans-Hermann Hoppe Foto

„As for the moral status of majority rule, it must be pointed out that it allows for A and B to band together to rip off C, C and A in turn joining to rip off B, and then B and C conspiring against A, and so on.“

—  Hans-Hermann Hoppe, buch Democracy: The God That Failed

Democracy - The God That Failed: The Economics and Politics of Monarchy, Democracy, and Natural Order (Transaction: 2001): 104.
Democracy: The God That Failed (2001)

Thomas Little Heath Foto
Hans Reichenbach Foto
Thomas Little Heath Foto

„The discovery of Hippocrates amounted to the discovery of the fact that from the relation
(1)\frac{a}{x} = \frac{x}{y} = \frac{y}{b}it follows that(\frac{a}{x})^3 = [\frac{a}{x} \cdot \frac{x}{y} \cdot \frac{y}{b} =] \frac{a}{b}and if a = 2b, [then (\frac{a}{x})^3 = 2, and]a^3 = 2x^3.The equations (1) are equivalent [by reducing to common denominators or cross multiplication] to the three equations
(2)x^2 = ay, y^2 = bx, xy = ab[or equivalently…y = \frac{x^2}{a}, x = \frac{y^2}{b}, y = \frac{ab}{x} ]Doubling the Cube
the 2 solutions of Menaechmusand the solutions of Menaechmus described by Eutocius amount to the determination of a point as the intersection of the curves represented in a rectangular system of Cartesian coordinates by any two of the equations (2).
Let AO, BO be straight lines placed so as to form a right angle at O, and of length a, b respectively. Produce BO to x and AO to y.
The first solution now consists in drawing a parabola, with vertex O and axis Ox, such that its parameter is equal to BO or b, and a hyperbola with Ox, Oy as asymptotes such that the rectangle under the distances of any point on the curve from Ox, Oy respectively is equal to the rectangle under AO, BO i. e. to ab. If P be the point of intersection of the parabola and hyperbola, and PN, PM be drawn perpendicular to Ox, Oy, i. e. if PN, PM be denoted by y, x, the coordinates of the point P, we shall have

\begin{cases}y^2 = b. ON = b. PM = bx\\ and\\ xy = PM. PN = ab\end{cases}whence\frac{a}{x} = \frac{x}{y} = \frac{y}{b}.
In the second solution of Menaechmus we are to draw the parabola described in the first solution and also the parabola whose vertex is O, axis Oy and parameter equal to a.“

—  Thomas Little Heath British civil servant and academic 1861 - 1940

The point P where the two parabolas intersect is given by<center><math>\begin{cases}y^2 = bx\\x^2 = ay\end{cases}</math></center>whence, as before,<center><math>\frac{a}{x} = \frac{x}{y} = \frac{y}{b}.</math></center>
Apollonius of Perga (1896)

Roger Shepard Foto
John Napier Foto
John Wallis Foto

„Suppose we a certain Number of things exposed, different each from other, as a, b, c, d, e, &c.; The question is, how many ways the order of these may be varied? as, for instance, how many changes may be Rung upon a certain Number of Bells; or, how many ways (by way of Anagram) a certain Number of (different) Letters may be differently ordered?
Alt.1,21) If the thing exposed be but One, as a, it is certain, that the order can be but one. That is 1.
2) If Two be exposed, as a, b, it is also manifest, that they may be taken in a double order, as ab, ba, and no more. That is 1 x 2 = 2. Alt.3
3) If Three be exposed; as a, b, c: Then, beginning with a, the other two b, c, may (by art. 2,) be disposed according to Two different orders, as bc, cb; whence arise Two Changes (or varieties of order) beginning with a as abc, acb: And, in like manner it may be shewed, that there be as many beginning with b; because the other two, a, c, may be so varied, as bac, bca. And again as many beginning with c as cab, cba. And therefore, in all, Three times Two. That is 1 x 2, x 3 = 6.
Alt.34) If Four be exposed as a, b, c, d; Then, beginning with a, the other Three may (by art. preceeding) be disposed six several ways. And (by the same reason) as many beginning with b, and as many beginning with c, and as many beginning with d. And therefore, in all, Four times six, or 24. That is, the Number answering to the case next foregoing, so many times taken as is the Number of things here exposed. That is 1 x 2 x 3, x 4 = 6 x 4 = 24.
5) And in like manner it may be shewed, that this Number 24 Multiplied by 5, that is 120 = 24 x 5 = 1 x 2 x 3 x 4 x 5, is the number of alternations (or changes of order) of Five things exposed. (Or, the Number of Changes on Five Bells.) For each of these five being put in the first place, the other four will (by art. preceeding) admit of 24 varieties, that is, in all, five times 24. And in like manner, this Number 120 Multiplied by 6, shews the Number of Alternations of 6 things exposed; and so onward, by continual Multiplication by the conse quent Numbers 7, 8, 9, &c.;
6) That is, how many so ever of Numbers, in their natural Consecution, beginning from 1, being continually Multiplied, give us the Number of Alternations (or Change of order) of which so many things are capable as is the last of the Numbers so Multiplied. As for instance, the Number of Changes in Ringing Five Bells, is 1 x 2 x 3 x 4 x 5 = 120. In Six Bells, 1 x 2 x 3 x 4 x 5 x 6 = 120 x 6 = 720. In Seven Bells, 720 x 7 = 5040. In Eight Bells, 5040 x 8 = 40320, And so onward, as far as we please.“

—  John Wallis English mathematician 1616 - 1703

Quelle: A Discourse of Combinations, Alterations, and Aliquot Parts (1685), Ch.II Of Alternations, or the different Change of Order, in any Number of Things proposed.

John Eardley Wilmot Foto
Theodor W. Adorno Foto

„The straight line is regarded as the shortest distance between two people, as if they were points.“

—  Theodor W. Adorno, buch Minima Moralia

Nun gilt für die kürzeste Verbindung zwischen zwei Personen die Gerade, so als ob sie Punkte wären.
E. Jephcott, trans. (1974), § 20
Minima Moralia (1951)

James Madison Foto

„To reconcile the gentleman with himself, it must be imagined that he determined the human character by the points of the compass. The truth was, that all men having power ought to be distrusted, to a certain degree.“

—  James Madison 4th president of the United States (1809 to 1817) 1751 - 1836

Madison's notes (11 July 1787) http://avalon.law.yale.edu/18th_century/debates_711.asp<!-- Reports of Debates in the Federal Convention (11 July 1787), in The Papers of James Madison (1842), Vol. II, p. 1073 -->
1780s, The Debates in the Federal Convention (1787)
Kontext: Two objections had been raised against leaving the adjustment of the representation, from time to time, to the discretion of the Legislature. The first was, they would be unwilling to revise it at all. The second, that, by referring to wealth, they would be bound by a rule which, if willing, they would be unable to execute. The first objection distrusts their fidelity. But if their duty, their honor, and their oaths, will not bind them, let us not put into their hands our liberty, and all our other great interests; let us have no government at all. In the second place, if these ties will bind them we need not distrust the practicability of the rule. It was followed in part by the Committee in the apportionment of Representatives yesterday reported to the House. The best course that could be taken would be to leave the interests of the people to the representatives of the people.
Mr. Madison was not a little surprised to hear this implicit confidence urged by a member who, on all occasions, had inculcated so strongly the political depravity of men, and the necessity of checking one vice and interest by opposing to them another vice and interest. If the representatives of the people would be bound by the ties he had mentioned, what need was there of a Senate? What of a revisionary power? But his reasoning was not only inconsistent with his former reasoning, but with itself. At the same time that he recommended this implicit confidence to the Southern States in the Northern majority, he was still more zealous in exhorting all to a jealousy of a western majority. To reconcile the gentleman with himself, it must be imagined that he determined the human character by the points of the compass. The truth was, that all men having power ought to be distrusted, to a certain degree. The case of Pennsylvania had been mentioned, where it was admitted that those who were possessed of the power in the original settlement never admitted the new settlements to a due share of it. England was a still more striking example.

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