He was criticized by Lenin in the 1909 essay Materialism and Empirio- Criticism.
He was criticized by Lenin in the 1909 essay Materialism and Empirio- Criticism. A disciple of the Enlightenment, he believed that any scientific term which refers to imperceptible quantities, like force, must be defined in term of perceptible sensat  ions. FTP, identify this philosopher, a long time professor of physics at Prague whose research in acoustics led to his name being given to the unit of the speed of sound.
He was criticized by Lenin in the 1909 essay Materialism and Empirio- Criticism.
Ernst Mach