But the extreme subtleties of human intellect are perhaps of little further use, than to afford an amusement to persons of curious speculation, and whose condition in human society procures them leisure for such enquiries. The same thing happens here, as in the subject of my Twelfth Essay, on the Liberty of Human Actions. The speculator in his closet is one man: the same person, when he comes out of his retirement, and mixes in intercourse with his fellow-creatures, is another man. The necessarian, when he reasons on the everlasting concatenation of antecedents and consequents, proves to his own apprehension irrefragably, that he is a passive instrument, acted upon, and acting upon other things, in turn, and that he can never disengage himself from the operation of the omnipotent laws of physical nature, and the impulses of other men with whom he is united in the ties of society. But no sooner does this acute and ingenious reasoner come into active life and the intercourse of his fellowmen, than all these fine-drawn speculations vanish from his recollection. He regards himself and other men as beings endowed with a liberty of action, as possessed of a proper initiative power, and free to do a thing or not to do it, without being subject to the absolute and irresistible constraint of motives. It is from this internal and indefeasible sense of liberty, that we draw all our moral energies and enthusiasm, that we persevere heroically in defiance of obstacles and discouragements, that we praise or blame the actions of others, and admire the elevated virtues of the best of our contemporaries, and of those whose achievements adorn the page of history.