( ( to me ) ( it ( ( is ( best ( thought ( of ( as ( ( a ( ( force or ) energy ) ) ( such ( as ( ( ( ( ( gravity , ) magnetism ) , ) or ) light ) ) ) ) ) ) ) ) ) . ) ) )
(ROOT (S (PP (TO to) (NP (PRP me))) (NP (PRP it)) (VP (VBZ is) (VP (RBS best) (VBN thought) (PP (IN of) (IN as) (NP (NP (DT a) (NN force) (CC or) (NN energy)) (PP (JJ such) (IN as) (NP (NP (NN gravity)) (, ,) (NP (NN magnetism)) (, ,) (CC or) (NP (NN light)))))))) (. .)))
to me it is best thought of as a force or energy such as gravity, magnetism, or light.
(ROOT (S (NP (NNP Gravity) (CC and) (NNP magnetism)) (VP (VBP are) (NP (DT both) (JJ common) (NNS forces))) (. .)))
Gravity and magnetism are both common forces.