The term “quickening” refers to the stage of pregnancy when a woman can feel the pre-born human move in her uterus. A woman can feel her fetus as early as 14 weeks.1
Many western democracies first banned abortion only after quickening. Abortion advocates like to use this fact to assert that because past societies were divided on how to value the fetus, we can’t expect modern societies to agree on the value of the fetus. Therefore, they argue, we should leave it up to each person to decide the value of the fetus.
However, looking at the development of the law in England, it seems what changed was the scientific understanding of the process of fertilization, not the value society has about human life. For example, William Harvey became famous for his study of human anatomy in the early 17th Century. However, without microscopes and other modern tools, scientists of his time believed in a variety of theories on when human life began. Harvey argued that the beginning of life was “incorporeal” and therefore could not be studied physically.2 This meant they could not say for certain that human life began before quickening. It makes sense, then, that they would have various ideas of how to value life before quickening—they weren’t sure it was human life.
However, with the discovery of the microscope and other scientific methods, scientists were able to study the process of fertilization in the early 19th Century. For example, in 1826, Prevost and Dumas discovered how frog zygotes divide. In 1827, Van Bauer discovered mammalian zygotes. Not long after, in 1837, England changed its abortion law to protect the fetus before quickening.
More discoveries followed. In 1843, Martin Barry was able to observe a rabbit sperm fertilize a rabbit egg, the first mammalian fertilization observed by humans. By the time Maitland Balfour published his influential book, Treatise on Comparative Embryology in 1880-81,3 medical science understood that human life began at fertilization. In 1892, the new country of Canada adopted a pro-life law that banned abortion, regardless of the age of the pre-born.
- Cornelia Van Der Ziel and Tourville, Jacqueline. Big, Beautiful & Pregnant: Expert Advice And Comforting Wisdom for the Expecting Plus-size Woman (Marlowe 2006). Retrieved February 15, 2007.
- Fielding Garrison, An Introduction to the History of Medicine, Saunders 1921, pp. 246–249.
- Garrison, pp. 528–529.