Only by virtue of ideas and judgments – unconscious though we may be of them when our feelings run high – can an indefinite state of mind pass into a definite feeling. The feeling of hope is inseparable from the conception of a happier state which is to come, and we compare with the actual state. The feeling of sadness involves the notion of a past state of happiness.
On excluding these conceptions from consciousness, nothing remains but a vague sense of motion which at best could not rise above a general feeling of satisfaction or discomfort. The feeling of love cannot be conceived apart from the image of the beloved being, or apart from the desire and the longing for the possession of the object of our affections. It is not the kind of physical activity but the intellectual substratum, the subject underlying it, which constitutes love. Dynamically speaking, love may be gentle and impetuous, buoyant or depressed, and yet it remains love. This reflection alone ought to make it clear that music can express only those qualifying adjectives, and not the substantive, love, itself.
Eduard Hanslick, 1854