We are not some casual and meaningless product of evolution. Each of us is the result of a thought of God. Each of us is willed, each of us is loved, each of us is necessary.
The moral legitimacy of all authority is founded on a respect for the rights of every human person. Without respect for the rights of every individual, authority can only resort to violence and force to obtain the compliance of its subjects.
The right to life is the most fundamental and basic right of the human person. All other inalienable rights are founded and develop from the right to life. Though there are rights that are more precious than the right to life, life is necessary for all other personal rights. Thus, respect for life is both the foundation and guarantee for the "essential goods of society" such as democracy, peace, and justice. 
1) CCC, 1930
2) Evangelium vitae, no 101