The answer to the questions revelant to the starting point of the human existence has periodically been related with the evolutionary process of the growth of the embryo. However, it has been founded more on theological theories, influenced by prevailing trends in each era, rather than on scientific, medical arguments. In the sphere of law, these questions are important for the determination of whether and since when, the embryo can be considered as a perfect individual and thus become a legal, protected estate and the object of special care by the legislator.