Homeopathy is presented as a modality of potential usefulness in the treatment of borderline patients refractory to psychoanalytic work. In these instances a minimally adequate centre of consciousness did not solidify from the identity with the psychoid stratum. In the view of Alchemy, this failure of the mind to separate from the unio naturalis or massa confusa could be remedied by a medicamentum spagyricum, an archtypal essence acting according to the simile principle, which was to be extracted from various substances. Homeopathy is described as a modern, clinically effective modification of the alchemistic method. Two cases example are given for illustration.