There was the whole philosophical movement of logical positivism, which said that if you can't see it, it doesn't exist; now we've seen atoms with electron microscopes. (discovermagazine.com)
Professional philosophers consider him the chief exponent of «nominalism,» a powerful late - medieval philosophical movement which denied that universal concepts and principles exist in reality» they exist only in our minds. (firstthings.com)
But Mr. Lewitt is also interested in issues beyond the flow of electricity: the movement of global capital, political power and philosophical movements like phenomenology, which concerns how our consciousness of our bodies affects our experience of reality. (nytimes.com)