When growth is harmonious and many-sided, it leads of necessity to out-growth, to escape from self.

For the expansive instincts are so many ways of escape from self which Nature opens up to the soul;--the sympathetic instincts, a way of escape into the boundless aether of love; the aesthetic instincts, a way of escape into the wonder-world of beauty; the scientific instincts, a way of escape into the world of mysteries which is lighted by the "high white star of truth." It is only when one of the expansive instincts is allowed to aggrandise itself at the expense of the others, that the consequent outgrowth of selfishness in what I may call the internal economy of one's nature begins to reflect itself in a general selfishness of character.

An instinct may readily become egoistic in its effort to affirm or over-affirm itself, to grasp at its share or more than its share of the child's rising life: and if it does, it may gradually suck down into the vortex of its egoism the whole character of the child as he ripens into the man.

But growth, as such, is anti-egoistic just because it is growth, because it is a movement towards a larger, fuller, and freer life: and it is restricted, even more than one-sided growth,--it is the apathy, the helplessness, the deadness of soul that overtakes, first the child and then the man, when his expansive instincts are systematically starved and thwarted,--which is the chief cause of his incarceration in his petty self.
If three-fourths of the moral evil in the world are due to malignant egoism, the source of the remaining fourth is, in a word, _sensuality_.

By sensuality I mean the undue or perverted development of the desires and passions of the animal self,--the desire for food and drink, the sexual desires, the desire for physical or semi-physical excitement, the animal passion of anger, and the rest.
As an enemy of the soul, sensuality is less dangerous, because more open and less insidious, than egoism.