"We begin with a radical conjecture: western philosophy was triggered by the intake of psychedelics..."

The Hidden Psychedelic History of Philosophy: Plato, Nietzsche, and 11 Other Philosophers Who Used Mind-Altering Drugs | High Existence:  "Plato’s philosophy was inspired by psychedelic intake, and western philosophy was inspired by Plato. The British philosopher Alfred North Whitehead (1861 – 1947) is known for claiming that, The safest general characterization of the European philosophical tradition is that it consists of a series of footnotes to Plato...

There, at the Temple of Demeter, participants would drink a potion—kykeon—containing barley, mint and water. It is widely believed that the kykeon contained too a psychedelic element. What that element was is widely contested, that it was psychedelic is less contested. Dr Albert Hofmann, the creator of LSD, argued that the compound was derived from the barley parasite fungus ergot, from which LSD is also derived. Hofmann writes,

[We can] assume that the barley grown [in the Rarian plain] was host to an ergot containing … the soluble hallucinogenic alkaloids. The famous Rarian plain was adjacent to Eleusis. Indeed this may well have led to the choice of Eleusis for Demeter’s temple … 

Within the darkened temple, participants had to exclaim: “I have fasted, I have drunk the kykeon”. What happened thereafter is, as the name of the event signals, mysterious—but in the Phaedrus Plato gives this account: 

[W]ith a blessed company—we following in the train of Zeus, and others in that of some other god—… saw the blessed sight and vision and were initiated into that which is rightly called the most blessed of mysteries, which we celebrated in a state of perfection … being permitted as initiates to the sight of perfect and simple and calm and happy apparitions, which we saw in the pure light, being ourselves pure and not entombed in this which we carry about with us and call the body, in which we are imprisoned like an oyster in its shell.

Thus is it quite plausible that psychedelics inspired the mind-body dualism prevalent in the west, not only in philosophy but also in religion: Plato’s influence on Christianity was substantial—Nietzsche even claimed that ‘Christianity was Platonism for the “people”.’ Regardless of the validity or not of Plato’s arguments, his thinking informed and enlightened our culture. Through a cave darkly, Plato came to see the light; this sunbeam of philosophy, science and reason sprang from the psychedelic experience..."