Dispersion and sadhana are two things that cannot go together. In sadhana one has to have a control over the mind and all its actions; in dispersion one is on the contrary controlled and run away with by the mind and unable to keep it to its subject. If the mind is to be always dispersed, then you cannot concentrate on reading either or any other occupation, you will be fit for nothing except perhaps talking, mixing, flirting with women and similar occupations.
Ref : Letters on Yoga Vol. II