“Mendicants, when these four bases of psychic power are developed and cultivated they lead to going from the near shore to the far shore. What four? It’s when a mendicant develops the basis of psychic power that has immersion due to enthusiasm, and active effort. They develop the basis of psychic power that has immersion due to energy, and active effort. They develop the basis of psychic power that has immersion due to mental development, and active effort. They develop the basis of psychic power that has immersion due to inquiry, and active effort. When these four bases of psychic power are developed and cultivated they lead to going from the near shore to the far shore.”
Iddhi (Sanskrit ṛddhi or siddhi) conveys the root sense “thriving, increase, success”. In the Atharva Veda we find samṛddhi and vyṛddhi in the sense “prosperity” and “misfortune” (eg. 10.2.10). As “success, completion” (of the sacrifice) we find ṛddhi at Śatapatha Brāhmaṇa 4.6.9.11. As far as I know, the Buddhist texts are where we first find iddhi in the sense of “psychic power” (or “spiritual magnification”, “heightened potency”; SN 51.10:3.2, SN 51.11:5.1). This sense is not attested in Sanskrit texts until later. The Yogasūtra elaborates many such powers and the methods of achieving them (3.17–3.37), but immediately warns that they are obstacles to samādhi (3.38). They are sometimes also numbered eight (Bhāgavata Purāṇa 3.20.53, 9.21.12), and we find this number also in Jain texts, which list various kinds of ṛddhi (or labdhi; eg. Ṭhāṇaṅga 5.168, Bhagavatisūtra 8.139). All these religions, however, aim at liberation, and do not regard the attainment of psychic powers as an end in itself. Probably the interest in such abilities was drawn from the broader ascetic culture, where to this day they exert a fascination. In the Indian context, such powers do not arise from the intervention of God or any other metaphysical means, but rather from the amplification of abilities latent in all beings. This teaching framework, accordingly, focuses on those things that form the bases (pāda) of psychic power. The powers themselves are mere adornments to the path, whose true purpose is to lead “from the near shore to the far shore”.
See SN 51.13 and SN 51.20 for further analysis.
“Enthusiasm” (chanda) is skillful desire to accomplish the path. The word chanda itself is neutral, and sometimes means “sensual desire” (kāmacchanda) or “consent” (Kd 2:23.1.5, Pli Tv Bi Pm:9.1).
The four factors map straightforwardly onto the final three factors of the noble eightfold path. “Enthusiasm” and “energy” both fall under “right effort”, while citta is “right immersion”, and vīmaṁsā is “right wisdom”.
Here, citta (“mental development”) means the development of the mind in immersion. This sense is common for citta in the context of the path, for example cittasampadā = samādhisampadā (DN 8:15.2); cittabhāvanā = samādhibhāvanā (SN 1.23:2.2). The same sense is apparent in cittānupassanā (“observation of the mind”) in satipaṭṭhāna, although there we see that the sense is somewhat broader, encompassing the mind as it goes through the process of development leading to immersion.