Srimad Bhagavatam Canto 10, Chapter 40, Text 06

 SB 10.40.6

eke tvakhila-karmani
 sannyasyopasamam gatah
jñanino jñana-yajñena
 yajanti jñana-vigraham
 
Translation: 
 
In pursuit of spiritual knowledge, some persons renounce all material activities and, having thus become peaceful, perform the sacrifice of philosophic investigation to worship You, the original form of all knowledge.
 
Purport: 
 
Modern philosophers pursue knowledge without bothering to worship the Supreme Personality of Godhead, and thus they naturally end up with meager, if not trivial, results.
Srimad Bhagavatam Canto 10, Chapter 40, Text 05
Srimad Bhagavatam Canto 10, Chapter 40, Text 07