MAN VS. ANIMAL
What’s the difference? Is it a matter of degree? Are we just a little smarter? Do we just have more and different instincts, like a religious instinct?
Gregory of Nyssa says that irrational animals act willingly but not from choice … the difference between the sensitive appetite (animal instinct) and the (free) will is that … the sensitive appetite is determinative to one particular thing … whereas the will … is indeterminate in respect of particular goods. Consequently choice properly belongs to the (human free) will, and not to the sensitive appetite which is all that irrational animals have. Wherefore irrational animals are not competent to choose… . An irrational animal takes one thing in preference to another because its appetite is naturally determinate to that thing. Wherefore as soon as an animal, by its sense or its imagination, is offered something to which its appetite is naturally inclined, it is moved to that alone, without making any choice (I-II,13,2).
The difference between humans and animals is in two powers that we have that the animal does not: reason and free will, or free choice. These powers are not instincts. Instincts are unfree. They are necessarily determined to one thing only, as we are hungry only for food and thirsty only for drink and tired only for sleep and have sexual desire only for sex. We are like the animals in having animal instincts. But we are more. Animals see and will only the concrete particular good. We understand the universal good, and therefore are free to choose between various particular goods. That is why we have free choice.
Only free choice is meritorious, praiseworthy, or blameworthy. God does not praise or blame us for our animal instincts. That’s why it doesn’t matter morally how you feel when you pray or when you choose (although good feelings help), only your free choice to believe God, hope in God, and love God, counts.
How often we act like animals! How often we let instinct determine behavior.
(1) Sometimes this is both good and necessary, like breathing or eating.
(2) Sometimes it is neither necessary nor good, like sinning by following our passions contrary to our reason.
(3) And sometimes it is not necessary—the instinct, once recognized, is freely followed—but it is good, like choosing to do for God what our natural instincts incline us to do anyway, like helping the suffering out of instinctive compassion, or giving thanks out of instinctive gratitude. Our instincts can help us as well as hinder us. Most of our life is lived on the animal level; we can use our instincts as we tame animals; we can transform that part of ourselves into the raw material (the “material causes”) for good choices. In fact much of moral character-building consists in forming and educating the instincts.
This is less onerous than it seems, since we have more good instincts than evil ones. Most of the things we do out of a combination of natural instinct and some free choice to follow the instinct have positive moral value—eating, reading, working, conversing, caring for our own and others’ welfare—because they are acts that are natural and rightly directed to good ends. That is the refutation of pessimism. The refutation of optimism is the fact that our instincts are not unfallen, so that all of the things we do and all of our instincts are prone to infection by some evil, especially the master evil of selfishness.
(4) And we can also act contrary to an instinct or animal passion, as animals cannot. For instance we can fast, as animals cannot; we can choose to offer up an innocent, orderly passion (hunger) for a higher good (God).
(5) We can also avoid sin by choosing to offer up and “mortify” a disordered passion instead of obeying it.
Kreeft, Peter. Practical Theology: Spiritual Direction from St. Thomas Aquinas (Kindle Locations 2770-2782). Ignatius Press. Kindle Edition.