matsuzawa developed his own eclectic philosophy of "conceptualism" (what would eventually be known as conceptual art). in its first phase, from 1957–1964, matsuzawa created surrealist works based on his "theory of psi" based on his interpretation of parapsychology. in his second phase from 1964 onward, matsuzawa reacted against the materialism of his earlier works and installations, and created a new anti-materialist art - art that existed with few or no objects as part of it. matsuzawa's idea was to encourage viewers to imagine art in their own mind's eye. his new form of art often consisted of absences - for example, a photo with part of it cut out or blanked. he also created "emissions" to be placed in a landscape, such as during his 1964 exhibition "independent '64 in the wilderness".