He observed that knowledge depends on experience, but does not believe that this dependence prevents us from understanding certain features of thought that must have preceded experience in order for learning to take place. His philosophical ideas are sometimes characterized 
He observed that knowledge depends on experience, but does not believe that this dependence prevents us from understanding certain features of thought that must have preceded experience in order for learning to take place. His philosophical ideas are sometimes characterized as idealism, because they retain the notion that ideal metaphysical realities, such as time and space, can be known, even in a world where knowledge depends on experience. He is also known for his political treatise, Perpetual Peace, where he outlines his famous "triangle." FTP, name this18th century German philosopher most famous for his Critique of Pure Reason and use of the categorical imperative.
He observed that knowledge depends on experience, but does not believe that this dependence prevents us from understanding certain features of thought that must have preceded experience in order for learning to take place.
Immanuel {Kant}