AbstractThe paper aims at defining the „nucleus”︁ of alchemy as an inseparable combination of chemical and spiritual characteristics. The alchemical process always reflected teleological thinking as the alchemists believed that nature itself strives for perfection. The symbol of perfection was gold as gold — like the Gods or God — is not affected by time. Critics of the alchemists in the Middle Ages (p. e.Chaucer) did not criticize the notion of an inherent teleology in nature, but they mistrusted the ability of the alchemists to succeed in their teleological strategy. To prove this it has often been pointed to the fact that no alchemist really obtained thelapis philosophorum: in other words the art of alchemy seems to have been completely unsuccessful. On the other hand, alchemy has had a long history which suggests that alchemy may not have been as unsuccessful as one might suspect. There might well have been a personal „reward”︁ for the individual alchemist, who worked in the laboratory, but this reward was a psychological, not a material one. Striving to perfect matter the alchemist subconsciously perfected his own soul. It should be added that the epistemological aims of the alchemists were totally different from those of the