No. *Survive*, possibly, and *function*, to a degree, if whatever injury deprives them of half their brain does so in childhood, while the developing brain is plastic enough to rewire itself; however, function *normally* is impossible. There is a particularly controversial neurologist here in the UK, named John Lorber, who has made claims that children who developed post-natal hydrocephaly (resulting in their brain tissue being highly compressed against the skull) not only developed normally but were in many cases above-average. An evaluation of his claims, many of which were unfortunately aired on public television, proved that he had both exaggerated the degree of compression of the brain by carefully selecting the scans he used as illustration, and exaggerated the degree of normality the subjects displayed. But that is as close as it comes to "operating with half a brain". What you might be thinking of is the result of the corpus callosum being severed -- that is the thick band of nerve tissue which connects the left and right hemispheres of the brain -- which effectively forces the two hemispheres to operate mostly independently (there is still communication through the midbrain and the brain stem, but this communication is not the same kind that the corpus callosum handles). This operation is still sometimes performed on people with severe epilepsy which does not respond to drug treatment, in order to "short-circuit" seizures which would otherwise involve the entire brain. However, although these people can and do lead normal lives, some interesting deficits do show up, mostly to do with face and object recognition and the more sophisticated aspects of handling language. But think for a minute. Many of us know people who have had strokes; and most people are familiar with the kind of cognitive and physical problems that people are left with after strokes, ranging from physical paralysis to an inability to recognize family members, with everything and anything possible in-between. Many more people know someone who has suffered a head injury, and had personality changes or changes to their physical abilities afterwards. And strokes and injuries like these usually involve relatively *small* areas of the brain. Now think how well you would do if the area of destruction were expanded....Not a pretty picture, is it.