Question: where does the phrase train of thought come from
[{'answer': 'Thomas Hobbes in his Leviathan', 'provenance': [{'wikipedia_id': '4646901', 'title': 'Train of thought', 'start_paragraph_id': 3, 'start_character': 79, 'end_paragraph_id': 3, 'end_character': 102, 'bleu_score': 0.668740304976422, 'section': 'Section::::Abstract.'}]}, {'answer': 'introduced and elaborated as early as in 1651 by Thomas Hobbes in his Leviathan'}, {'provenance': [{'wikipedia_id': '4646901', 'title': 'Train of thought', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 0, 'bleu_score': 1.0, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2583701507625228851}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '4646901', 'title': 'Train of thought', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 216, 'bleu_score': 0.943604326170661, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2583701507625228851}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '4646901', 'title': 'Train of thought', 'section': 'Section::::Abstract.', 'start_paragraph_id': 3, 'end_paragraph_id': 3, 'meta': {'evidence_span': ['The term "train of thoughts" was introduced and elaborated as early as in 1651 by Thomas Hobbes in his "Leviathan", though with a somewhat different meaning (similar to the meaning used by the British associationists):', 'The term "train of thoughts" was introduced and elaborated as early as in 1651 by Thomas Hobbes in his "Leviathan", though with a somewhat different meaning (similar to the meaning used by the British associationists):', 'The term "train of thoughts" was introduced and elaborated as early as in 1651 by Thomas Hobbes in his "Leviathan"']}}]}]