2/3 or 4
We need to be able to hold with respect all of the perspectives different people have on the same situation in our minds at the same time, for Jesus obviously sees and hears and understands all of the different perspectives people have on the same situation. 

Can we take abortion as an example?

As Catholics we have certainty that human beings are immortal, we simply cannot and will not cease to exist, and we believe that status is granted to us by a direct act of God while we are in the womb. Since immortality is for us a defining characteristic of what it means to be human, we are appalled and horrified by the idea of taking life in the womb.

But what about those who do not agree with us that human beings are immortal? If one seriously takes this perspective, then life in the womb is not yet fully human life, for the defining characteristics of being human from this perspective are not yet fully in place. Fetuses are evolving towards human life, but are not there yet.