Final answer:
Aristotle's view on when life begins, known as ensoulment, was believed to occur at 40 days after conception for males and 90 days for females. This concept has significantly influenced historical and religious perspectives on abortion.
Step-by-step explanation:
Aristotle, the ancient Greek philosopher, had a specific view concerning when life begins, which plays a role in discussions of abortion throughout history. He believed in the concept of ensoulment, which is the point at which a human being gains a soul. Aristotle, along with other historical figures such as Saint Augustine and Thomas Aquinas, influenced by Aristotelian thought, thought that ensoulment occurred at a certain time after conception, a period that was distinct for males and females: 40 days for boys and 90 days for girls. Aquinas, following Aristotle, indicated that it was not until the fetus became 'animated' or 'ensouled' that it was considered to be a human life with a soul, and so murder would not be committed until after this point. Up until the 19th century, this was the view the church officially adhered to, and it was not until Pope Pius IX altered the church's position to ensoulment occurring at conception.