What most separates the human from the subhuman? The stock catechism answer is that to be human is to have an immortal soul. But if evolution did happen, what qualities were infused by God into that soul that made it most distinct from the “souls” that animate lower animals?
To add to post 3 - the ability, as a being with self-consciousness, to recognise other selves: that is, being whom one can call “thou”, in contrast one’s own “I”.
No stone cannot respond to God as a created “I” to the Uncreated I that is God. IOW, they cannot have communion with God; they lack the capacity for it. Christians are “living stones” - but no stone is a living person.
Angels are spirits, so they don’t have that spirit which is the soul - they are spirits; we have spirits, because we are made of material & spirit together, which they are not, since they are free of matter.
Living material creatures other than man have souls - since the soul is the principle of life. So a dog or a chimp is a living being - but it is not endowed with self-awareness. Man is the ape who is also more than an ape precisely because his soul has what that of an ape lacks: the ability to interact with God & to know it. Apes are acted on by God, as are all created beings, from angels to atoms - but they cannot
respond in freedom & self-awareness to their Creator & Lord.
Man alone of all animals can do that, because he is designed so as to be capable of responding. Which is why he is the only animal capable of sin.
Robots can be programmed, but they cannot act of themselves: no robot is, nor can be, an “I”. Man is not God, so he cannot grant them that capacity. Behaving like a man, does not make one a man; one is a man, only by being created as one - and to do that, requires the power of God; for God is “beyond” all creatures; they are limited (to be limited, is what distinguishes creatures from God), wheras God is infinite in Being, Power, Goodness.
IOW, man is
irreducibly human - which is why someone with no limbs is a man, & why the most brilliantly contrived robot cannot be a man. Because we are talking about being, not doing. A cat drinking its milk can never be a baby human, even though baby humans drink milk. This is very important for pro-life issues.
Which means that man is like nothing in all creation - he is the ape who has the only thing that can make an angel happy: the ability to enjoy God. Apes can’t sin - they lack the capacity for doing so. Angels can’t sin - for they are confirmed in holiness. Man, alone, can sin and receive grace to repent. Anything so surreal as man could be dreamed up only by God.
So if we want an ape with a capacity to know God - that ape is man. Looking among other apes for such a thing is like looking for a lion by investigating tigers - one is looking in the wrong place; if apes could pray, they would be human.
If they cannot pray, then they are
irreducibly different from men: despite the percentages of similiarity to man. Numbers are irrelevant, because they are measuring what is quantitative - & the difference between man & other apes, is qualitative: being human is not measurable in percentages, neither is being similar to other creatures. One might as well distinguish colour by the measure of their prayerfulness, or ask for an omnipotence of sugar, or a goodness of tacks. The very idea is materialistic - so some very unintelligent experiments are carried out. Stupid methods & stupid projects in science lead to stupid results. The trouble with materialism, is that it behaves like the animal in the cartoon who covers his eyes & thinks the he can therefore not be seen. Which is bad for science - it doesn’t hurt faith, because faith has its own resources.
Sorry to woffle ##