Question: What is the PhilPapers topic for the person who influenced Henry David Thoreau?
Choices: philosophy-of-mind
edmund-husserl
architecture
mahatma-gandhi
albert-camus
ralph-waldo-emerson
karl-popper
martin-heidegger
heterosexuality
karl-marx
SPARQL: SELECT DISTINCT ?pv WHERE { ?e <pred:instance_of> ?c . ?c <pred:name> "human" . ?e_1 <influenced_by> ?e . ?e_1 <pred:name> "Henry David Thoreau" .  ?e <PhilPapers_topic> ?pv .  }
Program:
function: Find
inputs: Henry David Thoreau
function: Relate
dependencies: 0
inputs: influenced by
forward
function: FilterConcept
dependencies: 1
inputs: human
function: QueryAttr
dependencies: 2
inputs: PhilPapers topic
Answer: ralph-waldo-emerson