In The Disciplined Mind , I concluded that so varied a country as ours cannot agree on a single gritty and challeng-ing curriculum. His listing was provisional. This entire approach to the study of nature was strongly rejected by the early modern philosophers such as Francis Bacon , Thomas Hobbes , John Locke , and David Hume , all of whom preferred the word "understanding", in place of " intellectus " or "intelligence", in their English philosophical works. In synthesizing many of the ideas, programs, methods, brain research studies, and other contributions to literacy acquisition, I use Howard Gardner's theory of multiple intelligences MI theory as an organizing framework. No part of this publication—including the drawings, graphs, illustrations, or chapters, except for brief quotations in critical reviews or articles—may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording, or any information storage and retrieval system, without permission from ASCD. Major advances in the science of inheritance genetics and in biochemistry have clarified a number of inborn metabolic causes of many types of intellectual disability. Spatial ability is one of the three factors beneath g in the hierarchical model of intelligence.