What makes people irrational thinkers?

[polymath257]

Soul is more generally about the structure of our animate lives — it is our animation and how our animation functions. The Latin is anima. This includes but is not limited to the actions of the mind. It also includes the activities that the rest of your body is up to right now, including whatever your liver and your gall bladder are doing.

The simplest possible answer is "that which makes us alive." 

Greek philosophers defined the soul in various ways, some of which included some of the actions of the mind. 

As you might expect, Aristotle's answer was the most worked-out, consistent, and hard to argue with: "a system of abilities possessed and manifested by animate bodies of suitable structure." 

https://plato.stanford.edu/entries/ancient-soul/

I tend to get the hives whenever I see a 'that which...' definition. Such tend to assume there is only one such thing that does the job and that it is done in some uniform way.

So, if I find out that we are alive because of the differences of chemical potential between molecular oxygen and carbon dioxide together with the enzymes requires for respiration, does that make the 'soul' that difference in chemical potential together with those enzymes?

I suspect most people talking about souls don't see it like that.

As for Ari's definition, the 'system' seems to be much more complex and *physical* than what most people seem to imagine souls to be like.

While a reasonable definition, I would question whether the word is used like that in most discussions. If it is a technical definition, I guess it is acceptable.