A strong egoism is a protection against disease, but in the last resort we must begin to love in order that we may not fall ill, and must fall ill if, in consequence of frustration, we cannot love.

Indeed, the great Leonardo (da Vinci) remained like a child for the whole of his life in more than one way. It is said that all great men are bound to retain some infantile part. Even as an adult he continued to play, and this was another reason why he often appeared uncanny and incomprehensible to his contemporaries.

Humanity is in the highest degree irrational, so that there is no prospect of influencing it by reasonable arguments. Against prejudice one can do nothing.

As regards intellectual work it remains a fact, indeed, that great decisions in the realm of thought and momentous discoveries and solutions of problems are only possible to an individual, working in solitude.

If all the evidence put forward for the authenticity of religious teachings originates in the past, it is natural to look round and see whether the present, about which it is easier to form judgements, may not also be able to furnish evidence of the sort. If by this means we could succeed in clearing even a single portion of the religious system from doubt, the whole of it would gain enormously in credibility.

The conscious mind may be compared to a fountain playing in the sun and falling back into the great subterranean pool of subconscious from which it rises.

The analytic psychotherapist thus has a threefold battle to wage -- in his own mind against the forces which seek to drag him down from the analytic level; outside the analysis, against opponents who dispute the importance he attaches to the sexual instinctual forces and hinder him from making use of them in his scientific technique; and inside the analysis, against his patients, who at first behave like opponents but later on reveal the overvaluation of sexual life which dominates them, and who try to make him captive to their socially untamed passion.