James Allen
Belief

"Belief is the basis of all action, and, this being so, the belief which dominates the hearts or mind is shown in the life. Every man acts, thinks, lives in exact accordance with the belief which is rooted in his innermost being, and such is the mathematical nature of the laws which govern mind that it is absolutely impossible for anyone to believe in two opposing conditions at the same time. For instance, it is impossible to believe in justice and injustice, hatred and love, peace and strife, self and truth. Every man believes in one or the other of these opposites, never in both, and the daily conduct of every man indicates the nature of his belief."