In no more searching way can a man's faith be described than _in terms of the objects which thus he values most_. Wherever men find some consuming aim that is for them so supreme in worth that they sacrifice all else to win it, we speak of their attitude as a religion. The "religion of science" describes the absolute devotion of investigators to scientific research as the highest good; the "religion of art" describes the consuming passion with which some value beauty. When we say of one that "money is his God" we mean that he estimates it as life's highest treasure, and when with Paul we speak of others, "whose god is the belly" (Phil. 3:19), we mean men whose sensual life is to them the thing worth most. _What men believe in, therefore, is most deeply seen not by any opinions which they profess, but by the things they prize._ Faith, as Ruskin said, is "that by which men act while they live; not that which they talk of when they die." Many a man uses pious affirmations of Christian faith, but it is easy to observe from his life that what he really believes in is money. Where a man's treasure is, as Jesus said, his heart is, and there his faith is, too. Is there any doubt, then, what we most believe in when we are at our best? While in our lower altitudes it may be easy to believe that the physical is the ultimately real, in our upper altitudes we so value the spiritual world, that we tend with undeniable conviction to feel sure that it must be causal and eternal. Materialism is man's "night-view" of his life; but the "day-view" is religion. Tyndall the scientist was regarded by the Christians of his generation as the enemy of almost everything that they held dear. Let him, then, be witness for the truth which we have stated. "I have noticed," he said, speaking of materialism, "during years of self-observation, that it is not in hours of clearness and vigor that this doctrine commends itself to my mind."