Tanya - End of Chapter 8

Following what seem like disparaging remarks on secular studies, we see this:

"Unless he employs [these sciences] as a useful instrument, viz., as a means of a more affluent livelihood to be able to serve G‑d, or knows how to apply them in the service of G‑d and His Torah. This is the reason why Maimonides and Nachmanides, of blessed memory, and their adherents, engaged in them."