Philosophy and biology are vastly different worlds of thinking, which have common concepts. Among these, the idea of possibility is particularly significant presently. In many fields of contemporary biology and medicine, there is a sense of an expanding possibility of modifying living beings or structures. Things which were previously considered as impossible by many observers become feasible, although there are some doubts, for instance in the field of genetical therapy. Laboratory practice in biotechnologies is changing into largescale industrial production in medicine and agriculture. This general sense of feasibility reminds us of analogous situations in the history of science, for instance in chemistry at the end of the nineteenth century, when organic chemists became able to create new molecules almost at will.