First, the Sadhaka should not yearn for anything other than Bhagavan or Moksha, with no inner hankering whatsoever for anything material. Next, he (should) be fortunate (only decided through the Sukriti, or blessings and Grace accumulated through previous many births), to get a Guru of total abandon, who is a servant to his own Guru and Bhagavan and does not desire anything from his disciples, other than to transmit and share his knowledge, with them. If these preliminary conditions are met, the Sadhaka can attain Jnana, the knowledge of the Higher Self.