From Longman Dictionary of Contemporary Englishlie at the heart/centre/root of somethinglie at the heart/centre/root of somethingMAINto be the most important part of something, especially the main cause of it the issue that lies at the heart of the present conflict → lie
Examples from the Corpus
lie at the heart/centre/root of something• That view lies at the root of a government drive against the racist right.• The creation of a modernised democracy therefore lies at the heart of all our proposals.• As we shall find, this distinction lies at the root of Anselm's movements in his last years as archbishop.• We found that two key resource uses and two basic technologies lay at the root of lunar industry.• That is the issue which lies at the heart of Mr. Thorpe's case.• That question appears to lie at the heart of the highly publicized battle raging between Hasbro Inc. and Mattel Inc.• They overlook the human ability to negate, which lies at the root of thinking.• Basic compassion, not just for the old but for the younger generation too, lies at the heart of this idea. 