(Prabhupada's lecture - Śrīmad-Bhāgavatam 1.16.12 - Los Angeles, January 9, 1974)
Therefore knowledge must be taken from the Vedic literature. Veda means full knowledge. And that full knowledge, when it is properly utilized, then you can understand Kṛṣṇa. Vedaiś ca sarvair aham eva vedyaḥ [Bg. 15.15]. First of all you have to take to take to the Vedic literature for real knowledge. And when you come to the platform of real knowledge, then you can understand Kṛṣṇa. Before knowing Kṛṣṇa, you are in darkness. You are in darkness. Because it is said, vedaiś ca sarvaiḥ. Veda means knowledge. The ultimate goal of knowledge is to understand Kṛṣṇa. And therefore it is called Vedānta. Vedānta. Veda means knowledge, and anta means the ultimate. Vedānta. Vedānta philosophy. So Vedānta philosophy gives you direction that what is the object of knowledge. Athāto brahma jijñāsā: "Now object of knowledge is to understand the Supreme, the origin of everything."
That is object of knowledge, philosophy. Philosophy means science, anything. Science also trying, "What is the original cause of this creation? What is the original cause of life?" But because andhā yathāndhair upanīyamānāḥ [SB 7.5.31], the so-called philosophers, scientists, they have been taught by another unscientist, not scientist, so he is also not scientist, not philosopher, because he has been taught by another andha. Just like one blind man leads other blind man. So what he will get, knowledge? So therefore, according to Vedic civilization, it is enjoined, it is ordered, that "If you want to take knowledge," tad-vijñānārtham, "to understand the complete science," tad-vijñānārtham, "the spirit," sa gurum eva abhigacchet, "oḥ, you must approach a bona fide guru." Otherwise there is no knowledge. That is not knowledge.