Ma's character is critical to both Tom's growth and the reader's understanding of the idea of humanism, the third component of Steinbeck's social philosophy. Her most obvious purpose in the novel is to provide the physical expression of Jim Casy's ideals. Her actions consistently emphasize the theory of love and spirit haltingly defined by the preacher, that love and unity among men is necessary if people are to survive. For Ma, this unity begins with her family. Her relief at seeing Tom stems primarily from her fear that they would have to leave the state with the family broken. Ma also unknowingly expresses the pragmatic aspect of the social theory that Casy is struggling to understand. The preacher yearns to bring a practical spiritual help to those folks who are suffering, but doesn't know how. He spends his time thinking, wondering how to express this principle of love, while Ma immediately acts upon it. She is a pragmatist, focusing not on what might or should be, but how life is.
Although Pa is the "head" of the family, Ma is its backbone: It is her strength and support that keeps the family functioning. She knows each member's weaknesses and is accepting of them. Her ability to calm Tom enables him to evolve spiritually. Understanding his reckless temper and independent nature, she is frightened that in jail he has become "mean." She holds his face and scans his eyes, searching for truth that may not be expressed in words. This action foreshadows a later event in the novel in which she must hold Tom's face in the dark in order to "see" him.
For the majority of the novel's action, Ma works desperately to keep her family intact, not realizing that survival depends on embracing all persons as family. Her love operates on a deeper level, however, a level that indicates she seems to intuitively understand Casy's message that all people are holy and deserving of love because they all belong to one greater soul. Ma is always the first in the family to offer comfort and nourishment to others, just one indication of her subconscious, unconditional love. The larger concept of this love, that survival will only be possible through group action is glimpsed only fleetingly in her plea to Tom, "I got to dreamin'.… If we was all mad the same way, Tommy — they wouldn't hunt nobody down." She stops, not comprehending the validity of her dream.
