Huygens Quotes
![I have read your pleasant letter of 14th with singular pleasure. I discern your kind inclination and affection which I feel deeply obliged to requite [you] with service and friendship. Because of [my] inclination to do this, [and] in spite of your wish (of Constantijn Huygens], [I] am sending [you] along [with this letter] a painting, hoping that you will accept it, because it is the first momento which I offer you, Sir.... postscripttum]: My [dear] Sir: hang this picture in a bright light and in such a manner that it can be viewed from a distance. It will then sparkle at its best. (Rembrandt)](https://cdn.quotesdtb.com/img/quotes_images_webp/26/rembrandt-affection-best-bright-454426.webp)
Gradually... during the second half of the nineteenth century, the uncomfortable feeling of dislike of the action at a distance, which had been so strong in Huygens and other contemporaries of Newton, but had subsided during the eighteenth century, began to emerge again, and gained strength rapidly.
This was favoured by the purely mathematical transformation (which can be compared in a sense with that from the Ptolemaic to the Copernican system), replacing Newton's finite equations by the differential equations, the potential becoming the primary concept, instead of the force, which is only the gradient of the potential. These ideas, of course, arose first in the theory of electricity and magnetism or perhaps one should say in the brain of Faraday.
Willem de Sitter
But to return to the Newtonian Philosophy: Tho' its Truth is supported by Mathematicks, yet its Physical Discoveries may be communicated without. The great Mr. Locke was the first who became a Newtonian Philosopher without the help of Geometry; for having asked Mr. Huygens, whether all the mathematical Propositions in Sir Isaac's Principia were true, and being told he might depend upon their Certainty; he took them for granted, and carefully examined the Reasonings and Corollaries drawn from them, became Master of all the Physics, and was fully convinc'd of the great Discoveries contained in that Book.
John Theophilus Desaguliers
Quote in Rembrandt's letter to Constantijn Huygens (Amsterdam, 12 January 1639) on 3 paintings commissioned (in 1635 and started by Rembrandt already in 1635/36) by the imperial court, as cited in Painters on Painting (1963) by Eric Protter, p. 78 / Dutch original text in The Rembrandt Documents, Walter Strauss & Marjon van der Meulen - Abaris Books, New York 1979, p. 161.
Rembrandt
He supported himself by grinding lenses, which was no lowly menial occupation, as it is often presented to have been in romanticizing versions of the philosopher's life, but was rather a craft that drew extensively from Spinoza's serious interest in the science of optics. The quality of his wares was highly valued by other scientists of his day. The important Dutch astronomer Christiaan Huygens, who discovered Saturn's rings as well as one of its four moons, preferred Spinoza's lenses to all others. "The [lenses] that the Jew of Voorburg has in his microscopes have an admirable polish," Huygens wrote to his brother in 1667. The one part of the romantic lens-grinding legend that is sadly true is that the dust from the optical polishing was unhealthy for Spinoza, whose mother and brother had both died young from tuberculosis. He himself succumbed to the disease at the age of forty-four.
Baruch Spinoza
In mechanics Descartes can hardly be said to have advanced beyond Galileo. ...His statement of the first and second laws of motion was an improvement in form, but his third law is false in substance. The motions of bodies in their direct impact was imperfectly understood by Galileo, erroneously given by Descartes, and first correctly stated by Wren, Wallis, and Huygens.
René Descartes
