Ethel Lilian Voynich, née Boole was an Irish-born novelist and musician, and a supporter of several revolutionary causes. She was born in Cork, but grew up in Lancashire, England. Voynich was a significant figure, not only on the late Victorian literary scene, but also in Russian émigré circles. She is best known for her novel The Gadfly, which became hugely popular in her lifetime, especially in Russia.
Ethlyn T. Clough was an American newspaper publisher and editor. At the end of the 19th-century, five women in Michigan owned, edited, and personally managed their own newspapers, one of whom was Clough. For eighteen years, she published The Brooklyn Exponent. She was the recording secretary of the Michigan Woman's Press Association (MWPA).
"Etteilla", the pseudonym of Jean-Baptiste Alliette, was the French occultist and tarot-researcher, who was the first to develop an interpretation concept for the tarot cards and made a significant contribution to the esoteric development of the tarot cards to a wide audience, and therefore the first professional tarot occultist known to history who made his living by card divination. Etteilla also influenced the French divination professional Marie Anne Lenormand. In the years 1783–1785 Etteilla published his work Manière de se récréer avec le jeu de cartes nommées tarots, which is still considered the standard reference work of Tarot cartomancy. Etteilla published his ideas of the correspondences between the tarot, astrology, and the four classical elements and four humors, and in 1789 he published his own tarot deck, which, however, differed significantly from the classic tarots such as the Tarot de Marseille in terms of structure and card designations.
Esther (Etty) Hillesum was a Dutch Jewish author of confessional letters and diaries which describe both her religious awakening and the persecutions of Jewish people in Amsterdam during the German occupation. In 1943, she was deported and murdered in Auschwitz concentration camp.
Euclid was an ancient Greek mathematician active as a geometer and logician. Considered the "father of geometry", he is chiefly known for the Elements treatise, which established the foundations of geometry that largely dominated the field until the early 19th century. His system, now referred to as Euclidean geometry, involved new innovations in combination with a synthesis of theories from earlier Greek mathematicians, including Eudoxus of Cnidus, Hippocrates of Chios, Thales and Theaetetus. With Archimedes and Apollonius of Perga, Euclid is generally considered among the greatest mathematicians of antiquity, and one of the most influential in the history of mathematics.
Euclid of Megara was a Greek Socratic philosopher who founded the Megarian school of philosophy. He was a pupil of Socrates in the late 5th century BC, and was present at his death. He held the supreme good to be one, eternal and unchangeable, and denied the existence of anything contrary to the good. Editors and translators in the Middle Ages often confused him with Euclid of Alexandria when discussing the latter's Elements.
