Logic is good to a point, incorporate emotion in time, and there is reason.
Emotion, Logic and Reason | Cogito Ergo

Perhaps the bacteria and virus are biological primal forms that have no emotion or logic. They are pure programming (with some logic) and serve one function.  Through random mutation they survive to live another day. What, then, is in between these primitive forms and animal life (humans included)? I am not sure, but emotions evolved in the higher species for a particular purpose maybe – that being the ability to adapt to an environment without waiting for a mutation, but to do it freelance style, so to speak. How would this be accomplished? The answer must be by incorporating emotion!