We may *illustrate the function of conscience* by reference to a question now agitated in our community,—the question as to the moral fitness of the moderate use of fermented liquors. In civilized society, intoxication is universally known to be opposed to the fitnesses of body and mind, an abuse of alcoholic liquors, and an abuse of the drinker’s own personality; and it is therefore condemned by all consciences, by none more heartily than by those of its victims. But there still remains open the question whether entire abstinence from fermented liquors be a duty, and this is a question of fact. Says one party, “Alcohol, in every form, and in the least quantity, is a virulent poison, and therefore unfit for body and mind.” Says the other party, “Wine, moderately used, is healthful, salutary, restorative, and therefore fitted to body and mind.” Change the opinion of the latter party, their consciences would at once take the other side; and if they retained in precept and practice their present position, they would retain it self-condemned. Change the opinion of the former party, their consciences would assume the ground which they now assail. Demonstrate to the whole community—as it is to be hoped physiology will do at no distant day—the precise truth in this matter, there would remain no difference of conscientious judgment, whatever difference of practice might still continue. *Conscience*, like all the perceptive faculties, *prompts to action in accordance with its perceptions*. In this respect it differs not in the least from sight, hearing, taste. Our natural proclivity is to direct our movements with reference to the objects within the field of our vision, to govern our conduct by what we hear, to take into our mouths only substances that are pleasing to the taste. Yet fright, temerity, or courage may impel us to incur dangers which we clearly see; opiniativeness or obstinacy may make us inwardly deaf to counsels or warnings which we hear; and motives of health may induce us to swallow the most nauseous drugs. In like manner, our inevitable tendency is to govern our conduct by the fitness of things when clearly perceived; but intense and unrestrained appetite, desire, or affection may lead us to violate that fitness, though distinctly seen and acknowledged.