sankhya-yogau prthag balah
pravadanti na panditah
ekam apy asthitah samyag
ubhayor vindate phalan
(Karma-yoga-Action in Krsna(divine) Consciousness (Text 4, Ch 5)
Meaning: Only the ignorant speak of devotional service [karma-yoga] as being different from the analytical study of the material world. Those who are actually learned say that he who applies himself well to one of these paths achieves the results of both.