Following paragraphs illustrate the variety of ideas he shared with his students:
Light and Darkness: All the darkness of the universe cannot obscure the light of one little lamp. So is it with your understanding of the spiritual idea which heals sickness and sin. It may seem to you to be small. It may seem but a tiny filament of understanding glowing incandescent with the white light of divine Love; yet it carries the brightness of health and joy into the black darkness of sickness, and the dull gloom of distress. When error comes to you and argues that your lamp is too small for the very dark place, silence it. Turn on it and deny the lie. Push the button, and you will prove that the blacker the darkness the brighter your light. Then the voice of the tempter is silenced, and the warmth of gratitude radiates from the light of Love.
Eyes and Vision: The eye does not see. It is merely the instrument or agency through which sight is manifested. The violin does not make the music that the master hand produces through it. The harmony that comes through the violin exists in Mind, and the wood and strings are the material agency for bringing it to human comprehension. We shall have less trouble with our eyes when we give more seeing power to Mind. It is foolish to wait for impaired vision to awaken us to the fact that Mind sees. It is right to take proper care of our eyes and not to overwork or abuse them; but if we give as much thought to the part that Mind takes in seeing as we now give to our eyes when they misbehave, we shall have better organs of sight. The more credit we give to Spirit for what we value, the more completely and perfectly will our material necessities be supplied. It is not the eye but the mind that sees. You can describe what you saw in a dream last night. In the same way you can hold a rose in your hand, shut your eyes and still see the rose. (See Science and Health 487:6-12.)
The Diamond Rule: The Golden Rule and Diamond Rule are reciprocal. The Diamond Rule is “Think of others as you would have others think of you.” Through this Diamond Rule of right thinking, we may enter the field of boundless opportunity, the field where thought reigns unlimited by time and circumstance. Wherever we may be and whatever may be our activities, we can direct and control our own thinking. Our thought may wander and, darting hither and thither, may seem hard to hold; but if we persistently bring it back as often as it breaks away, the aggregate will be what we want. In the realm of thought, each of us has his own domain into which none can enter unless we sign his passport. Circumstances and people may at times prevent our doing what we would, but in Science they cannot prevent our thinking as we should.