Brigham Young has many wonderful tidbits scattered throughout his years as prophet. A friend pointed out the following snippet:
[T]hink, brethren, think, but do not think so far that you cannot think back again…
Now that is simply a beautiful quote. What does it mean? For the sake of completeness let me give you Brigham’s explanation:
In the eastern country there was a man who used to go crazy, at times, and then come to his senses again. One of his neighbors asked him what made him go crazy; he replied, “I get to thinking, and thinking, until finally I think so far that I am not always able to think back again.” Can you think too much for the spirit which is put in the tabernacle? You can, and this is a subject which I wish the brethren instructed upon, and the people to understand. The spirit is the intelligent part of man, and is intimately connected with the tabernacle. Let this intelligent part labor to excess, and it will eventually overcome the tabernacle, the equilibrium will be destroyed, and the whole organization deranged. Many people have deranged themselves by thinking too much.
The thinking part is the immortal or invisible portion, and it is that which performs the mental labor; then the tabernacle, which is formed and organized for that express purpose, brings about or effects the result of that mental labor. Let the body work with the mind, and let them both labor fairly together, and, with but few exceptions, you will have a strong-minded, athletic individual, powerful both physically and mentally.
When you find the thinking faculty perfectly active, in a healthy person, it should put the physical organization into active operation, and the result of the reflection is carried out, and the object is accomplished. In such a person you will see mental and physical health and strength combined, in their perfection. We have the best opportunity afforded any people to cultivate these properties of man.
So we should be careful thinkers. But don’t get so busy thinking that you forget to do your home teaching.