- Artificial ending (All heart)
- Unhappy/Unfinished ending (All logic)
On the other hand, there are the unhappy endings. The world operates on something I purposely did not mention before... and that is hope. Happy endings, when built properly and handled well, embed hope in the audience. I know in a lot of ways, people want to keep it as honest as possible. HELLO, this is fiction!! We read it [and I write it] to escape from the "honesty" [some call it reality] of my own life. Or if it's nonfiction, then to rejoice in the depth and survivorship of the human soul, not to wallow in its misery.
Both of these are ways to annoy readers. [And yes, I know Lincoln has a great quote about fooling/pleasing people, so don't bother reminding me.] But you need to be true to what your own heart says and what your logic tells you. Just because you have an evil person in your book doesn't mean that your hero will be strong enough [mentally and/or physically] to defeat them or that the villain will be stupid/weak enough to succumb to the hero.
When you factor in "heart", you also factor in a great number of other things, so that even though you may have planned for your hero to be strong and your villain to be weak... there are things like fate, destiny, and chance that can get in your way.
To non-writers, you may think up the perfect way to logically handle a situation, but you would be forgetting the human factor, the factor that involves another beating heart that you have no control over. You can try with all your heart to make something work, and you can wish on stars too. But sometimes that doesn't work... in fact, a lot of times that doesn't work. In the meantime, you'd be wasting precious space in your heart. In life you can use all heart or all logic, I try to use both.