The determination of when this ensoulment occurs during the development stages of a human -- from conception to birth -- has changed over the last several centuries.
Either of these points can be seen as the moment of conception.
Religious Pro-life proponents claim that human life begins at conception, which could lead to the conclusion that abortion is murder.
However, 'life' is a quality that plants, bacteria, dogs, termites, humans, and other living entities have.
The sensitive soul is what separates plants from animals, and provides animals the ability to move and to interact with the world around them.
The intellective soul is what separates humans from all other animals, and allows humans to think and reason.
24 weeks - Age at which the fetus can first feel pain, according to an June 2010 BBC News article.