At the end of the 20 th century we can say that the enthusiasm and expectations about natural sciences that was present at the end of the 19 th century in many respects have not been fulfilled. There are too many dangers created by man and/or science: storage of toxic waste, variability, mutation of pathogens, pharmacons, chemicals, radiation, and so on. There is a really wide scale where these cosmic, ecological, technical and human factors, changes of climate etc. combine in front of our eyes. All these have a reasonable effect on the morbidity and mortality scales. In many respects it is the consequence of the harmful effects created by man itself and modern science that the biologically possible extension of human life and health including the sound function of the nervous system which was also made possible in theory by modern science never became reality. The most common and most vulnerable target organ of the exogenous dangering effects is the nervous system.

        Key words: holistic approach, vulnerability of nervous system, psychoimmunology, toxic agents