Truth is what is real and factual. Application of logic yields new facts, new understanding of truth.
But logic breaks where emotions rule.
We see this easily in betting games. The term “pot committed” comes from poker. A person’s reasoning and logic goes out the window when he has committed so much money in the pot that he disregards his actual chances of winning and keeps throwing money into an already losing proposition.
We see this in science where a scientist can become so emotionally committed to a theory that no amound of contrary facts will sway him. Witness the late Fred Hoyle and his commitment to his Steady State theory. Regardless of how much evidence pointed to a Big Bang or similar theory, he kept on insisting that the universe was in a steady state.
We see this so often than in politics. People get so committed to a certain ideology that their intellect has taken a permanent leave of absence.
And of course religion. Forget the facts, the Earth is 6000 years old. Because an old book says so.
Science owns the realm of facts and truth. Politics and religion should be confined to areas where certainty is elusive – like what solutions to apply to global warming or praying for a loved one’s life. But when science comes up with a definite answer to how we should mitigate climate change, politics should step aside and let the factual solution be applied. And when the doctor with scientific certainty prescribes the medicine that will save your wife’s life, you can still pray – but you should not reject the medicine. Only when there are uncertainties regarding the medicine, then it boils down to judgement, ideology, religion or hunch. But when there is certainty, let facts and logic prevail.
Facebook discussions are rampant with emotions and virtually devoid of logic. And the way you can see this is the incessant display of logical fallacies; Straw Man, Argumentum Ad Hominem, No True Scotsman, Appeal to Authority or other Red Herrings. And the way you handle it is to keep calm, remain on the subject, observe the facts, listen carefully and stay with logic.
Logic: The science or art of exact reasoning, or of pure and formal thought, or of the laws according to which the processes of pure thinking should be conducted; the science of the formation and application of general notions; the science of generalization, judgment, classification, reasoning, and systematic arrangement; the science of correct reasoning. [1913 Webster]