Sometimes the news media will report "The drought has caused large brush fires..." No, the drought did not cause fire, a spark caused the fire.
There are many causes of emotion, such as the existence of life itself, but without the false self, the ego, there would be no emotion, even if all the other causes are there.
believe that it is irrationality or illogic that sparks negative emotions
They lead to all emotions, including so-called "positive" ones.
A "positive emotion" is one that makes our ego feel good, such as a feeling of fullfillment, or a feeling of worth, and a "negative emotion" is one that makes ego feel bad, such as a feeling of emptiness or lack of worth.
In Buddhism this is referred to poetically as "the round of life and death", or samsara. Enlightenment is the escape from it.
(to all) What originally sparked your love of wisdom in your personal experience?
Understanding truth gives a feeling of fulfillment that is addictive to the ego. But it is a kind of drug that eventually destroys the ego from within.