Immediate reality is conditional upon individual consciousness. Thus the individual real existence of man also lies first and foremost in his consciousness. But this is as such necessarily ideational, and thus conditioned by the intellect and by the sphere and substance of the intellect's activity. The degree of clarity of consciousness, and consequently of thought, can therefore be regarded as the degree of reality of existence. But this degree of thought, or of clear consciousness of ones own existence and that of others, varies very greatly within the human race itself according to the measure of natural intellectual power, the extent to which this is developed, and the amount of leisure available for reflection. - On Psychology
I observed once to Goethe ... that when a friend is with us we do not think the same of him as when he is away. He replied, "Yes! because the absent friend is yourself, and he exists only in your head; whereas the friend who is present has an individuality of his own, and moves according to laws of his own, which cannot always be in accordance with those which you form for yourself."
The intellectual attainments of a man who thinks for himself resemble a fine painting, where the light and shade are correct, the tone sustained, the colour perfectly harmonised; it is true to life. On the other hand, the intellectual attainments of the mere man of learning are like a large palette, full of all sorts of colours, which at most are systematically arranged, but devoid of harmony, connection and meaning.