There is much foolish talk in these days about the relations of opinion to practice. It is not uncommonly assumed, even when it is not directly stated, that a man’s beliefs are not of any particular moment, provided that his conduct is right. The underlying assumption is that beliefs exercise little or no influence on conduct. But does not all history, does not all human experience, give the lie to this assumption? Ideas have ever been the most potent engines in social and moral change. They have upset the thrones of kings, and they have reversed the destinies of nations. See what miracles have been wrought in our own time by the idea of national unity. Remember again what convulsions and upheavals of society were caused in the age of our fathers, and threaten again to be brought about in the age of our sons, by the idea of the equality and brotherhood of mankind. And as with nations and peoples, so also with the individual man. An ideal of life, firmly grasped, is an untold power for good or for evil. An ideal is a sort of prophecy, which works its own fulfilment; it haunts the dreams, and it inspires the waking hours. To keep a definite goal in view and to press ever forward towards it—to know what you desire to attain, and to strain every nerve for its attainment—this it is which will give a distinctness, a force, a savour to your conduct—a savour of life unto life, if the ideal be well chosen, but a savour of death unto death, if it be some unworthy aim, such as riches or ambition or pleasure or worldly success in any of its manifold forms.