why we need to train the sensibility

Again from Schiller:

"The greater part of humanity is too much harassed and fatigued by the struggle with want, to rally itself for a new and sterner struggle with error. Content if they themselves escape the hard labour of thought, men gladly resign to others the guardianship of their ideas, and if it happens that higher needs are stirred in them, they embrace with eager faith the formulas which State and priesthood hold in readiness for such an occasion. If these unhappy people earn out sympathy, we should be rightly contemptuous of those others whom a better lot has freed from the yoke of necessity, but their own choice continues to stoop beneach it."

And now,

"These men prefer the twilight of obscure conceptions, where feeling is livelier and fancy fashions comfortable images at its own pleasure, to the beams of truth which dispel the fond delusion of their dreams. On the very deceptions which the hostile light of knowledge should dissipate, they have based the whole structure of their happiness, and are they to purchase so dearly a truth which begins by depriving them of everything they value? They would need to be already wise, in order to love wisdom...."

"It is, therefore, not enough to say that all intellectual enlightenment deserves our respect only insofar as it reacts upon the character; to a certain extent it proceeds from the character, since the way to the head must lie through the heart. Training of the sensibility is then the more pressing need of our age, not merely because it will be a means of making the improved understanding effective for living, but for the very reason that it awakens this improvement."

On the Aesthetic Education of Man