The Psychology of Self-Esteem

This is not the attitude of a genuinely mature adult. An adult, too, of course, may recognize (and, indeed, must often
be prepared to recognize) that there are things he does not yet know and needs to learn. But he does not entertain
such a category as that which is known to others but unknowable to him—unknowable in principle. This does not
mean that his goal is to possess encyclopedic knowledge. It means that, within the sphere of his first-hand concerns,
of his own actions and goals, he regards himself as competent to know that which he needs to know and to acquire
whatever knowledge his interests and purposes demand. It means that he does not resign himself to the permanently
unknown, when and if the knowledge is available and is relevant to his activities. It means that he does not regard
himself as a second-class citizen psycho-epistemologically. It is this attitude, consistently maintained, that marks a
man's entry into full adulthood, i.e., into full self-responsibility.