The last couple of days I’ve put up a couple of posts regarding animals displaying surprising amounts of intelligence–dolphins making simple tools, monkeys using money.
In view of the fact that man is distinguished from the animals by having a rational soul (in contrast to their sensitive souls), this raises a question: Just how much reason do you need to have a rational soul?
There is no Church teaching on this, but here are a few thoughts on the subject:
1) It is not just any kind of intelligence that results in a rational soul. Certain kinds of intelligence a creature may have in spades without it amounting to the gift of reason. For example: survival skills. The ability to, in its own native habitat, do such things as hunt, forage for food, reproduce, or–in the case of some species (like spiders, bees, ants, termites, wasps, and beavers) build shelter or similar structures does not count as reason. Reason involves a more abstract reasoning facility than these kinds of skills.
2) Mere ability to tool use tools also does not count as reason. The monkeys who were taught to use money as a tool to get what they want, or a chimp who’s been taught to communicate using a symbolic keyboard, this does not indicate reason.
3) Neither does the ability to make simple tools, such as primates who strip leaves off twigs to get a good termite-digging twig or the dolphins who rip sponges off the sea floor to get nose guards.
4) If the capacity to make simple tools, or to use more sophisticated ones, is not sufficient for the kind of reason that coincides with the presence of a rational soul, what kind of reason does? I would suggest that a useful way of trying to figure it out is by looking at the development of reason in our own species.
5) When humans are conceived–at the one cell, zygote stage–they have no more actual intelligence than the zygotes of other species. An adult dog has more actual intelligence than a zygote human. What human zygotes do have is rational souls that, as their neurology develops, will increasingly manifest their potential until the amount of actual intelligence a human possesses zooms past that of adult dogs and every other species on the planet.
6) At some point in this development, a typical human reaches what we call the "age of reason" or the "age of accountability" or similar terms. I propose that this age is the most promising stage of human development to look to when trying to settle our question. If we judge that children of a certain age have the gift of reason–reason sufficient to be gravely morally accountable for their actions–then this is plausibly the kind of reason that a rational soul is meant to manifest.
7) Kids below this age are not judged to be gravely accountable for their actions. They are incapable of committing mortal sin because they lack the reason to do so. They have rational souls below this age, of course, but their neurology has not yet developed to the point that they have the full and actual gift of reason, only a partial or potential exercise of reason.
8) My conjecture is that this is the dividing line to which we should look in determining whether a non-human creature has reason. If this is the kind of reason we focus on in human development, the same benchmark should be used (mutatis mutandis) for other creatures.
9) The other creatures on Earth, of course, all fall below this level of reason–or at least so it seems. But the test might be applied to new creatures we discover offworld someday–if there is any life out there. If we find them to have intelligence–and specifically the capacity for moral reasoning–equivalent to a human at or past the age of reason then we should presume that they have rational souls, as we do.
10) I also conjecture one other thing as a sign of reason: If they possess the concepts of God or the afterlife without being taught them by another species then they also should be presumed to possess rational souls. I acknowledge that we might one day teach a chimp to use the sign for "God" correctly in sentences, but being taught a symbol or even a concept by a more intelligent species is not what I would regard as indicative of the presence of a rational soul.
11) The Church does not have a formal teaching on when the age of reason is, but it is commonly assumed to be about age seven years–earlier in some children, later in others. Parents who have seen multiple children pass through this age range also note that they perceive a change taking place in the sophistication of moral reasoning of their children at about this time.
12) This has an application even to creatures here on Earth: If the above conjecture is correct, a non-human species–even here on Earth–could have the intelligence (and specifically the moral reasoning capacity) of anything up to that of a six or seven year old child without it being indicative that the creature has a rational soul.
13) The conjecture would thus suggest that we should still regard terrestrial animals as animals–not possessors of rational souls and not the subjects of moral rights–even if they display impressive levels of abstract intelligence or proto-moral reasoning, as long as this level falls below the level that a human at the age of reason would have.
14) This, however, is only conjecture. The sources of revelation, while they are clear on the fact that terrestrial animals are included within mankind’s stewardship and fit for his use, are not explicit on every consideration that could be raised. The ancient Hebrews did not know about the existence of certain species of highly-intelligent animals (e.g., gorillas), nor did they know very much about the intelligence of others (e.g., whales, dolphins). In fact, the Hebrews weren’t big on doing intelligence tests even on the animals they were familiar with.
15) It is therefore possible that further research and reflection on certain highly intelligent animal species could–at least hypothetically–result in development of doctrine regarding what does and does not possess a rational soul, and when precisely the age of reason is in humans. I don’t say that because I think it likely that any of these species have rational souls. I just mention it in recognition of the fact that the sources of revelation are limited in what they tell us and that the above is what it is: conjecture.
