Here’s an interesting quote from William Walker Atkinson:

“Most of us have heard the old proverb which states that “As a man thinketh, so is he.” And most of us accept the spirit of the idea that a man’s character, disposition, activities, and general personality are dependent largely upon the general character of his thoughts.

This being so, and it also being true that a man is able to control the general character of his thoughts, it logically follows that every awakened Ego is the creator of the character and personality of the individual whose self it is.

Philosophers teach us that there is a law of polarity manifesting in everything. That is to say, that in everything there is found the presence of the two poles, viz., the positive and the negative. We find this law manifest in the mentality and character of every individual. There is always to be found the positive elements of mentality and character, and the negative elements thereof.

There is always to be the “two-sidedness” in individuals. Every individual finds within himself a constant struggle between these two opposing elements — the positive and the negative.

Upon the decision of this battle depends largely the advancement, success, welfare, and progress of the individual.

Goethe has well said: “In my breast, alas, two souls dwell, all there is unrest. Each with the other strives for mastery, each from the other struggles to be free.”

The ordinary individual seems to be content to remain as a passive spectator of this struggle; but the individual of the awakened Ego takes a part in the struggle, and by throwing the weight of his free will into the balance, he brings down the scales on the positive side.”