In the simple case, explicit reasoning is reasoning which:
However, the exact definition may vary based on context. For example, explicit reasoning might be operationalized as imaginary verbal reasoning taking place in a person's inner monologue (ie, in auditory working memory). In other cases, we might have a much higher standard, eg actual symbolic logic written on an external medium such as paper. So, reasoning can be more and less explicit, along several dimensions.
Explicit reasoning is one of many modes of reasoning by which humans may reach conclusions. While it is not always the best mode of reasoning, it has the advantage of being scrutable, ie, open to inspection. This makes it easier to correct, in particular through imaginary verbal reasoning modelled after dialogue (ie, mentally responding to yourself as if you were another person, with critiques and corrections). Since it can easily be recorded, it can also be subject to feedback from many other people, which can further improve the quality of this type of reasoning. Also, explicit reasoning can easily be chained together to reach less obvious conclusions....