Dr. Robert Klitz­man had rec­om­mend­ed that his father try an exper­i­men­tal can­cer chemother­a­py that proved dead­ly. That expe­ri­ence has haunt­ed Dr. Klitz­man ever since, and led to his writ­ing a book exam­in­ing how we, as indi­vid­u­als and a soci­ety, decide what exper­i­ments on humans are safe enough. This book explores how hor­rif­ic Nazi exper­i­ments in con­cen­tra­tion camps first prompt­ed the devel­op­ment of guide­lines on human exper­i­ments. But cur­rent reg­u­la­tions are increas­ing­ly inad­e­quate and con­tro­ver­sial. Human exper­i­ments on genes, can­cer, stem cells, infec­tions, depres­sion, and oth­er dis­eases are trans­form­ing our lives, but pose enor­mous eth­i­cal dilem­mas. Pre­cepts from the Old Tes­ta­ment and var­i­ous philoso­phers help, but new tech­nolo­gies present ever-new chal­lenges. Klitz­man probes how research ethics com­mit­tees wres­tle with these quan­daries, strug­gling to weigh future risks and ben­e­fits and to ensure jus­tice and con­sent, but have them­selves become con­tro­ver­sial as sci­ence advances. This book illu­mi­nates how we all must bet­ter appre­ci­ate and under­stand the moral quan­daries that sci­ence and tech­nol­o­gy increas­ing­ly pose as we enter the future of medicine.