The public's comprehension of Modern Art depends upon understanding the relationship of the artist to his work and to the public, Thomas M. Messer, Director of the Institute of Contemporary Art, commented last week. He called the painter a "philosopher who expresses through shapes and forms what is most important to him," and whose painting thus becomes evidence of original and significant thought.

Speaking on "Images in Modern Art" at the third lecture in the Thursday afternoon series, Messer defined images as mental pictures to which form has been given. He stated that as a person's comprehension of the world becomes more involved, his images of such things as man, woman, and emotion also become more complex.

Attempt at Truth

Numerous colored slides illustrated Messer's point: the object of art is to say things never said before. During his comparison of Boucher's sensuous "Venus" with De Kooning's grotesque figure of "Woman," Messer commented that modern art attempts to tell the truth even if the subject is not pretty.

A question and answer period followed the lecture. When asked to comment on the statement that modern art is ugly art, Messer replied that new reality does not strike one as beautiful. Reality, to those unaccustomed to it, tends to shock.

Messer, a Czechoslovakian immigrant, directed the annual Boston Arts Festival this year. He is teaching two courses in the Summer School.

Hans J. Morgenthau of the University of Chicago will lecture at 3 p.m. today is Burr B. Director of the Center for the Study of American Foreign and Military Policy, Morgenthau will discuss "Disarmament: Conditions and Consequences."