Question: who taught that governments should be ruled by philosopher-kings
[{'answer': 'Plato', 'provenance': [{'wikipedia_id': '1908606', 'title': 'Philosopher king', 'start_paragraph_id': 1, 'start_character': 13, 'end_paragraph_id': 1, 'end_character': 18, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1908606', 'title': 'Philosopher king', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 392, 'bleu_score': 0.8805993382776641, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6978664610241741223}, 'section': 'Section::::Abstract.'}]}]