Any science is based on the faculty of expert discrimination. By skillful definition of isolated and interactive components one becomes expert in any field. Ultimately the most intelligent person can isolate the spirit soul from matter and describe the properties of matter and spirit as both isolated and interactive components of reality. The proliferation of innumerable philosophical speculations is due to differing modes of perception within the material world. As stated in Bhagavad-gītā (15.15) , sarvasya cāhaṁ hṛdi sanniviṣṭo mattaḥ smṛtir jṣānam apohanaṁ ca: the Supreme Personality of Godhead is situated in everyone’s heart and awards a particular degree of knowledge or ignorance according to one’s desire and merit. Thus the Lord Himself is the basis of the mundane process of philosophical speculation, for He creates differing and alternating modes of perception within the conditioned souls. It is to be understood that one can acquire perfect knowledge only by hearing directly from Lord Kṛṣṇa and not by hearing from conditioned philosophers who imperfectly perceive the creation of the Lord through the screen of their personal desires.