Can somebody explain the Samkhya theory of creation in a clear and concise manner? It is crucial because Vedantins also later adopted this view on creation. So this is arguably the standard Hindu creation theory.
The Samkhya theory of creation is that there are two kinds of entities in the Universe, Purushas or souls and Prakriti or matter/energy, and that when Prakriti is in the presence of a Purusha, it evolves into a variety of different forms. Here is what Ishwara Krishna's Samkhya Karika, a defining text of the Samkhya school, says:
Primal Nature is not an evolute; Mahat, etc., the seven, are evolvents and evolutes; the group of sixteen is evolute; the Spirit is neither an evolute nor an evolvent.... (The union) of the Spirit (with the Nature) is for contemplation (of the Nature); (the union) of the Nature (with the Spirit) is for liberation. The union of both (i.e., the Spirit and the Nature) is like that of a lame man with a blind man. The creation is brought about by that (union). From the Nature proceeds the intellect; thence ego, thence the group of sixteen, and from five out of this group of sixteen, the five gross elements.... Ego is self-consciousness. Two kinds of creations proceed from it, viz., the group of eleven and the five-fold subtle elements. From The Vaikṛta Ego (proceeds) The Group Of Eleven, Characterized By Sattva. From The Bhūtādi Ego (proceeds) The Group Of Subtle Elements Which Is Tāmasa. From The Taijasa Ego (proceed) Both. The organs of sense are eye, ear, nose, tongue and skin. Speech, hands, feet, anus, and the organ of procreation are called the organs of action. Here, the mind is of the nature of both (organs of sense and action). It is determinative, and is also an organ on account of similarity. This diversity (of the organs) and the diversities of external things, arise from the specific modifications of the Attributes.... The subtle elements are non-specific, from these five, the five gross elements are produced. The latter are called specific and are tranquil, violent and delusive.