Moral realism is false

[genkaus]

Over the past decades, numerous discoveries in neurology and evolutionary psychology have shown beyond any reasonable doubt that our moral intuitions ultimately stem from the shaping of our brain by evolution and that WITHOUT any such emotional intuition, no moral system can be built from reason alone.
This is well illustrated by the study of the brains of psychopaths: since they lack the moral emotions, they don’t consider as true most fundamental moral principles (like avoiding to create suffering, trying to promote the happiness of others) although they are quite able to reason well.

I'll stop you right there. There are quite a few things that are wrong with your basing of morality on evolutionary intuitions.

First of all, you need to learn the distinction between human morality and evolutionary morality.

Morality is a guide on how to act. The aspects of our actions that are grounded in our genetic code can be referred to as evolutionary morality. Examples of these can be found in many other species as well.

Human morality, on the other hand, is not encoded in our genes and is subject to choice. In fact, any action that is not subject to choice is not considered to have a moral dimension.

For example, some species of ants have the biological imperative to sacrifice themselves for their society. They do not have the capacity to act against this instinct. In human terms, we would not consider this action either good or bad, because there could have been no alternative.

Humans, on the other hand, may have an inclination to act in a certain way, but they are not bound by the choice. So while discussing human morality, we cannot simply refer to our biological inclinations to act in a certain way.

What you are doing here is taking some of our biological inclinations (empathy, altruism etc.) and ignoring others (selfishness, violence). You assume that a certain type of human instincts should be used as a moral guide and the rest should not. Why did you pick specifically those emotional intuitions as a basis for morality and not any of the others?

As I have said, no moral system can be grounded by mere logic or factual analysis alone, at some point moral intuitions (due to Evolution) are always going to come into play.
Take for example the possibility of torturing a baby just for fun: almost every human being would react with disgust and say it is wrong. Neuroscience has proven that such reaction does not stem from a rational consideration of all facts but rather from instinctive gut feelings.
Afterward, people try to rationalize their belief by backing them up with arguments and mistakenly think they feel this disgust because of their reasoning although it is the other way around.

While I acknowledge the existence of an emotional response to any event, I most strenuously object to using those as a guide to morality. You are incorrect in your assumption that no moral system is or can be grounded in logical and factual analysis of the matter.

Let's consider your "torturing a baby" question.

Here we have an action - "torturing a baby" and the purpose "to have fun".

To judge the morality of this action, we first need to determine the basic requirements that must be met for morality to apply.

First of all, the person should have freely chosen to torture the baby, i.e., his actions should not be a result of a biological imperative or any other form of duress.

The required assumption for this freedom is that the person is the sole owner of his life and his actions and is therefore morally justified in directing his actions to his own purposes.

The same concepts apply to the baby as well. Since the baby is also the sole owner of its life, any action by the torturer would violate the premise by which his own actions can be justified. That is why such an action would be wrong - not because it offends someone's sensibilities.