But, above all, that thought was kept out of their minds by the fact that they saw they were really useful, as in fact they were to the whole Rostov family. Their usefulness did not depend on making the patient swallow substances for the most part harmful (the harm was scarcely perceptible, as they were given in small doses), but they were useful, necessary, and indispensable because they satisfied a mental need of the invalid and of those who loved her—