by Will Durant
* Dryden, in Absalom and Achitophel (1681), had recently described comets as “rising from earthy vapours ere they shine in the skies.”
* Leonardo da Vinci, about 1500, made drawings of a pendulum and an escapement mechanism. Galileo formulated some laws of the pendulum, and conceived the idea of a pendulum clock in 1641, but he died before applying the idea in practice. Camerini in 1656 made a small pendulum clock just a few months before Huygens.
* Cf. our current conception of light as visible radiant energy. All bodies are assumed to be continually emitting radiant energy. Radiation from objects warmer than the human body are felt by the skin as heat; but if the temperature of the object is sufficiently increased it will become luminous—i.e., some of its emitted radiation will be felt by the eye as light.
* By which any power of a binomial (an algebraic expression composed of two terms connected by a plus or minus sign) can be found by an algebraic formula instead of being worked out by multiplication. Newton had been partly anticipated in this theorem by Viète and Pascal.
* Later physicists preferred Huygens’ undulating theory on the ground that Newton’s corpuscular hypothesis did not account satisfactorily for phenomena of diffraction, interference, and polarization. Contemporary physics would like to combine the two views to explain phenomena apparently involving both corpuscles and waves. The photons or quanta of today recall Newton’s corpuscles. The ether is at present in disrepute.
†Cf. Albert Einstein, Relativity (New York, 1900), 88.
* Kepler’s laws (1609, 1619): 1. The planets describe elliptical orbits, in which the sun is one focus. 2. The line joining a planet to the sun sweeps over equal areas in equal times. 3. The square of the period of revolution of a planet is proportional to the cube of its average distance from the sun. This last formula led to the law of inverse squares.
* Chiefly De Cive (1642, 1647); The Elements of Law, published in two parts (1650) as Human Nature and De Corpore Politico; Philosophical Rudiments (1651); Elementorum Philosophiae, Sectio Prima: De Corpore (1655); De Homine (1658); many fragments on mathematics; translations of the Iliad and the Odyssey; Behemoth (1670); and an autobiography in verse (1679).
* In discussing the subjectivity of general or class ideas, Locke points out that the term species, as applied to organisms, is a mental construct and convenience; that the objective world contains no separate species but only separate individuals, all descending “by easy steps and a continued series of things that in each remove differ very little one from all other . . . till we come to the lowest and most inorganical parts of matter. . . . The boundaries of the species, whereby men sort them, are made by men.” 134
* In the first edition of the Essay Locke admitted no “free will” except as freedom from external restraint. In later editions he modified this determinism to allow that the mind can suspend the execution and satisfaction of its desires. 144
* In the latest physics our sensations are caused not by any known “matter,” but by subtle energies whose material substratum is unknown and hypothetical.
* Spinoza’s emendation of this “psychophysical parallelism” may help us to see some sense in Geulincx. God, or nature, acts in two concurrent aspects and streams: the physical sequences of the objective world, including our bodies; and the mental sequences of the subjective world, including our feelings, thoughts, and volitions. Neither of the two streams ever causes the other, for both are merely two sides—the outside and the inside—of one process, one duplex stream of events.
† Compare this theological statement with the determinist doctrine that every motion in matter, and every mental state, is caused by the total past, and that the immediate physical agents, and the self and “free will,” are the instruments of this total force, or cosmic energy, acting through matter and mind.
* Later van den Ende served the Dutch as a secret agent in Paris; he was captured by the French government, and was hanged (1676). 6
* Cf. the Sophia of the Book of Wisdom, and the Logos of the Fourth Gospel.
* Some scholars question the acquaintance of Spinoza with Jan de Witt. Cf. Clark, The Seventeenth Century, 223n.
* Language usually makes Nature feminine and God masculine; by identifying them Spinoza does more justice to the female or productive principle in reality. Perhaps the masculinization of God was part of the patriarchal subordination of woman, who is, after all, the main stream of human reality.
* Nietzsche echoes these definitions. “What is good? All that enhances the feeling of power . . . What is happiness? The feeling that power is increasing.” 128
* “Even this early,” said Spengler, “Leibniz laid down the principle that Napoleon grasped . . . more clearly after Wagram, viz., that acquisitions on the Rhine and in Belgium would not permanently better the position of France, and that the neck of Suez would one day be the key of world-dominance.” 7
* Locke wrote of the mind at birth as “white paper,” 34 but did not use the phrase tabula rasa (clean slate), which was Aquinas’ translation of a passage in Aristotle’s De anima. 35
* Descartes’ formula was mv—force is mass times velocity. Leibniz, on the basis of Galileo’s work, changed this to mv 2. The current formula is ½mv 2.
* Cf. Jacques Boulenger, The Seventeenth Century (New York, 1920), 243: “It is evident that she had nothing to do with the Revocation of the Edict of Nantes.” And the Encyclopaedia Britannica, XIV, 693a: “The Revocation and the dragonnades have been unjustlylaid to her charge.” Voltaire had long ago concluded likewise (Works, [New York, 1927] XXIa-290).
* The baïonette was manufactured at Bayonne as early as 1500, but seems to have had its first large-scale use at Ypres in 1647. 22
* From the French text in Fellows and Torrey, The Age of Enlightenment, 91–95. The letter was first published by d’Alembert in 1787. Its authenticity remained doubtful until 1825, when a copy of it was found in Fénelon’s own hand. 32
