Question: who gave the cyclical theory of socail change
[{'answer': 'Arthur Schlesinger', 'provenance': [{'wikipedia_id': '5876640', 'title': 'Cyclical theory (American history)', 'start_paragraph_id': 10, 'start_character': 0, 'end_paragraph_id': 10, 'end_character': 18, 'bleu_score': 1.0, 'section': 'Section::::The foreign-policy cycle.\n'}]}]