Cold logic is my name for reasoning that follows a rule past the point where it stops helping people. It is firm, consistent, and blind to feeling, flaw, and circumstance. It turns lives into numbers and treats efficiency as the only virtue. It is tempting because it looks airtight on paper.
The idea is not new. J. J. C. Smart called following a rule, even when breaking it would be better, “superstitious rule worship”. Max Weber separated reasoning about means from reasoning about ends. The eugenics movement is the clearest case. Sterilization programs were sold as improvement, and the suffering they caused was left out of the sum.
The opposite failure is real too. Warm sentiment, meaning choices made purely from feeling, brings its own chaos and harm. I see the two as ends of one scale. Lean cold for safety and technical choices, where feeling clouds judgment. Lean warm for relationships and community, where compassion is the point. And remember that even the most rational system has to stay tied to the people it governs.
For public figures, cold logic describes a position, never a person. That is how libertarianism is handled on this site.