It belongs to our reasoning

[morningtrain]

This paragraph as below is so difficult for me to follow. I got a few question here.

First, I don't understand "we think the way we do because of the kind of animals we are."
What does "do" mean? I'd like to know the meaning of the whole sentence.

Second, I do not find out what it refers to. Somebody says it indicate our reasoning.
I roughly understand the sentence as "we always think in a specific situation."

Why do we need to have "it belong to our reasoning"? Any comments would be appreciated.

================================================== =======
Eagleton, Terry, On Evil (New Haven & London: Yale U. Press, 2010)

("Thomas Aquinas taught that our reasoning is closely bound up with our bodies. Roughly speaking, we think the way we do because of the kind of animals we are. It belongs to our reasoning, for example, that it always goes on within a specific situation. We think from inside a particular perspective on the world. This is not an obstacle to grasping the truth. On the contrary, it is the only way we can grasp it. The only truths we can attain to are those appropriate to finite beings like ourselves. And these are the truths of neither angels nor anteaters. Overreachers, however, refuse to accept these enabling constraints. For them, only truths which are free of all perspective can be authentic. The only valid viewpoint is the God's-eye viewpoint. But this is a vantage point from which we humans would see nothing at all. For us, absolute knowledge would be utter blindness.

[Raymott]

This paragraph as below is so difficult for me to follow. I got a few question here.

First, I don't understand "we think the way we do because of the kind of animals we are."
What does "do" mean? I'd like to know the meaning of the whole sentence.

Second, I do not find out what it refers to. Somebody says it indicate our reasoning.
I roughly understand the sentence as "we always think in a specific situation."

Why do we need to have "it belong to our reasoning"? Any comments would be appreciated.

================================================== =======
Eagleton, Terry, On Evil (New Haven & London: Yale U. Press, 2010)

("Thomas Aquinas taught that our reasoning is closely bound up with our bodies. Roughly speaking, we think the way we do because of the kind of animals we are. It belongs to our reasoning, for example, that it always goes on within a specific situation. We think from inside a particular perspective on the world. This is not an obstacle to grasping the truth. On the contrary, it is the only way we can grasp it. The only truths we can attain to are those appropriate to finite beings like ourselves. And these are the truths of neither angels nor anteaters. Overreachers, however, refuse to accept these enabling constraints. For them, only truths which are free of all perspective can be authentic. The only valid viewpoint is the God's-eye viewpoint. But this is a vantage point from which we humans would see nothing at all. For us, absolute knowledge would be utter blindness.

"We think the way we do (think)" = "We think as we do" = "We think this way"
"We think this way because this is the type of animal we are."
"Thinking like this belongs to the type of reasoning we do. The type of thinking we do is related to the situation."

[emsr2d2]

Whenever you see "do" used in this kind of construction, you can replace it with the original verb and (almost always) you will get the meaning:

I walk the way I do because my feet are very small = I walk the way I walk because my feet are very small.
He speaks the way he does because he is deaf = He speaks the way he speaks because he is deaf.
I eat what I do because I know nothing about nutrition = I eat what I eat because I know nothing about nutrition.
She cooks as well as she does because her father was a chef = She cooks as well as she cooks because her father was a chef. Note that this can also be worded: She cooks so well because her father was a chef.

[morningtrain]

Thanks a lot, Raymott!!! So helpful. Now it's all clear to me.

Thanks emsr2d2. It's kind of you to explain so easily for me that way.