In the material energy, the principal manifestations are eight, as above mentioned. Out of these, the first five manifestations, namely earth, water, fire, air and sky, are called the five gigantic creations or the gross creations, within which the five sense objects are included. They are the manifestations of physical sound, touch, form, taste and smell. Material science comprises these ten items and nothing more. But the other three items, namely mind, intelligence and false ego, are neglected by the materialists. Philosophers who deal with mental activities are also not perfect in knowledge because they do not know the ultimate source, Kṛṣṇa. The false ego-“I am,” and “It is mine,” which constitute the basic principle of material existence-includes ten sense organs for material activities. Intelligence refers to the total material creation, called the mahat-tattva. Therefore from the eight separated energies of the Lord are manifest the twenty-four elements of the material world, which are the subject matter of sāṅkhya atheistic philosophy; they are originally offshoots from Kṛṣṇa’s energies and are separated from Him, but atheistic sāṅkhya philosophers with a poor fund of knowledge do not know Kṛṣṇa as the cause of all causes. The subject matter for discussion in the sāṅkhya philosophy is only the manifestation of the external energy of Kṛṣṇa, as it is described in the Bhagavad-gītā.
Ref >> Srila Prabhupada Vani.