Vaiṣṇava ācārya said: "Yes, spirit is the basic principle. Matter is false. That's all right. But that spirit is not void. There is spiritual construction. As in the material world there is material construction, in the spiritual world there is spiritual construction." So that spiritual construction is not known to other philosophers than the Vaiṣṇava philosophers.
So the Lord Caitanya's philosophy—that is the greatest contribution to the world—that these living entities who are hankering after happiness by different process. By material process, by philosophical process, by mental concoction or mental process they are trying, and Lord Kṛṣṇa also said—they are trying—but that happiness is available when your senses or consciousness are pure. The same philosophy is also Lord Caitanya's philosophy. He says that jīvera svarūpa haya nitya kṛṣṇa-dāsa (CC Madhya 20.108-109).